Given the complexity of individuals’ lives and the multifaceted nature of the problems that clients experience, social workers need knowledge in which area?

Politics, economics and biology.

Explanation:

Exercising social work implicates a wide variety of psychosocial services to persons, familiar groups, and small groups related to a diversity of human problems in their lives. Social work takes place both in public and private contexts. It concerns an evaluation of interaction within a person's biological, psychological, political, and social experiences, which gives the professional a guide to intervening clinically.

by using  production possibilities graph.  opportunity costs are key expenses in financial matters and are utilized as a part of registering money saving advantage investigation of a venture. such expenses, be that as it may, are not recorded in the record books but rather are perceived in basic leadership by processing the money costs and their subsequent benefit or misfortune.