Which of the following scenarios would you expect to yield the greatest private marginal benefit?

a. Bob, who is a slob, takes a class in organization.

b. Art, who is smart, returns to school to obtain his second Bachelor's degree.

c. Suzy Q, who is two, learns to talk.

d. Little Pete, who is sweet, learns to cook from his grandma.

e. Your future spouse, who lays around the house, learns to do laundry.