Pero o por lo menos

[michaelbr]

In this phrase "Me he vuelto mediocre y convencional, ______ soy más feliz que antes y estoy muy satisfecho con lo que tengo."
The options are: 1) por qué 2) pero 3) por lo menos 4) aunque
For me, the following answers would be correct:
1) if it's porque and not por qué, it should be correct, right?
2) pero is the correct answer
3) why por lo menos is not correct? It seems to me that either pero or por lo menos would be correct

[AngelicaDeAlquezar]

"Pero" introduces a contrast or a contradiction on what one says.
Here it is used because being happy can be opposed to being mediocre. In any case confusion might have arisen with "aunque". But "por lo menos" does not introduce any contradiction, but an exception.

- Juan se enojó o, por lo menos, eso parecía.
Juan was angry, or at least that's what it seemed.

- Ya no hay perros en el edificio; por lo menos no están haciendo ruido.
There aren't any dogs in the building; at least they aren't making any noise.

- La carretera está cerrada. Por lo menos, cuando oí las noticias estaba cerrada.
The road is closed. At least when I heard the news, it was closed.


Also, "por lo menos" is a synonym of "como mínimo" when talking about things that can be measured.

- Tengo por lo menos veinticinco años estudiando inglés.
I have been studying English for at least 25 years.

- Si te vuelves vendedor, puedes ganar por lo menos diez mil pesos al mes.
If you become a salesman, you can make at least 10,000 pesos a month.

- Hay que caminar por lo menos treinta minutos diarios para estar en forma.
There's need to walk at least 30 minutes every day to stay fit.


And finally, "por lo menos" can also be used to talk about something that can be "rescued" from a somehow negative situation.

- Si ya no somos amigos, por lo menos devuélveme los libros que te he prestado.
If we aren't friends anymore, at least give me back the books I have lent you.

- No pude llegar a la junta pero por lo menos no fui el único ausente.
I couldn't make it to the meeting but at least I wasn't the only one absent.

- La comida de ese restaurante es malísima; por lo menos no es muy cara.
The food in that restaurant is horrible; at least it's not too expensive.

[michaelbr]

"Pero" introduces a contrast or a contradiction on what one says.
Here it is used because being happy can be opposed to being mediocre. In any case confusion might have arisen with "aunque". But "por lo menos" does not introduce any contradiction, but an exception.

- Juan se enojó o, por lo menos, eso parecía.
Juan was angry, or at least that's what it seemed.

- Ya no hay perros en el edificio; por lo menos no están haciendo ruido.
There aren't any dogs in the building; at least they aren't making any noise.

- La carretera está cerrada. Por lo menos, cuando oí las noticias estaba cerrada.
The road is closed. At least when I heard the news, it was closed.


Also, "por lo menos" is a synonym of "como mínimo" when talking about things that can be measured.

- Tengo por lo menos veinticinco años estudiando inglés.
I have been studying English for at least 25 years.

- Si te vuelves vendedor, puedes ganar por lo menos diez mil pesos al mes.
If you become a salesman, you can make at least 10,000 pesos a month.

- Hay que caminar por lo menos treinta minutos diarios para estar en forma.
There's need to walk at least 30 minutes every day to stay fit.


And finally, "por lo menos" can also be used to talk about something that can be "rescued" from a somehow negative situation.

- Si ya no somos amigos, por lo menos devuélveme los libros que te he prestado.
If we aren't friends anymore, at least give me back the books I have lent you.

- No pude llegar a la junta pero por lo menos no fui el único ausente.
I couldn't make it to the meeting but at least I wasn't the only one absent.

- La comida de ese restaurante es malísima; por lo menos no es muy cara.
The food in that restaurant is horrible; at least it's not too expensive.
Thanks so much for such detailed explanation, it's much appreciated.