Nora's marginal benefit exceeds her marginal cost by the greatest amount when she is consuming 10 units of product Y. To maximize her net benefit, Norah should:

a.consume more than 10 units of the product.

b.have stopped consuming the product before he reached 10 units.

c.give up more of good Y for another good

d.stop consuming at 10 units.

e.not enough information to answer the question.