After families, schools are the most important and obvious means through which children learn
a. loyalty.
c. religious beliefs.
b. social norms, values, and beliefs.
d. patriotism.

The correct answer for this question is this one: "b. social norms, values, and beliefs." After families, schools are the most important and obvious means through which children learn social norms, values, and beliefs. One reason for this is simply that children spend a significant amount of time at school: so it's very likely to influence them. 

Sector is best defined as (part).