A customer has purchased one pack of 100 pairs of disposable face masks. The price of the second pack is $45, and the buyer estimated its net benefit from buying this second pack to exceed $50. What should the buyer do?

Select one:

a. The buyer should not buy the second pack as buying the second pack will increase total benefits by more than total costs.

b. The buyer should not buy the second pack as buying the second pack will increase total benefits by less than total costs.

c. The buyer should buy the second pack because the marginal benefit of the second pack is so high that its marginal cost does not matter any more.

d. The buyer should buy the second pack because the marginal benefit of the second pack exceeds the marginal cost.