In production, firms produce goods in batches of one or a few products designed to customer specification.

d. small batch

Explanation:

Small batch production refers to a type of production that will see a company producing a good in limited quantity so as to satisfy a specific customers specifications and requirements. They are usually used for jobs that require custom made goods.

For instance, when you need to print shirt for a family reunion and you go to a shop that prints shirts and they print 100 of them. This is a small batch production for your family.

answer; is usually (less than) the socially optimal level of consumption;

answer; microeconomics;