Which statement about risk-averse individuals is correct?

a. None of the alternatives is correct.

b. They are willing to pay no more than the actuarially fair premium for health insurance.

c. If they can afford it, they always choose to buy health insurance.

d. For them, each additional increment to income increases utility by an amount smaller than the previous increment.

e. For them, the actual utility of income is shaped like a convex curve.