The correct answer to this open question is the following.
Unfortunately, you did not attach the passaged or a link to it. You neither attach the options for this question.
However, trying to help, we can comment on the following.
The monks discussed in the passage above gathered together in monasteries.
We can say it was in the monasteries because historically, monks gathered or met in the buildings called monasteries. Usually, it was a big old building where monks lived and had the facilities to pray and have meetings to discuss issues of their time.
They lived their whole life in monasteries because they were secluded, devoting their lives to god and pray.