Identify the correct statement about experience rating in group insurance.

a$.$ It provides a direct economic incentive for risk managers to control claims.

b$.$ The experience of smaller groups is considered sufficiently statistically credible or reliable to determine premiums completely.

c$.$ The smaller the group, the more credit the group receives for its own claims experience.

d$.$ Most small companies have experience$-$rated premiums in which the group's own claims experience affects the cost of coverage.

Question $7$