Why are there so few guests at the funeral?

it is a religious funeral.
the funeral is held on a weekday.
the residents are not allowed to come.
monsieur mersault has no friends or family.

There are few guests at the funeral because, Its a religious funeral and not everyone practices the same religion, The funeral was held on a weekday and many people work late and don't have the time to go, Residents aren't allowed to come which is very important because the person who passed might have had resident friends or family, and Monsieur had no friends nor family members so no one came. This all concludes to the funeral being empty/ with every few people.

b would have to be the answer