Which of the Following Is a Reason Why Employers Are

Which of the following is a reason why employers are the predominant source of insurance?

A) insuring at the firm level reduces the extent to which insurance has moral hazard effects.
B) insuring at the firm level allows insurers to create large insurance pools with a predictable distribution of medical risk.
C) employee compensation in the form of medical expenditures is not taxed.
D) both b and c are correct.