Although for smokers the marginal benefit from smoking may exceed the marginal cost of smoking, the negative effects of second-hand smoke may increase the marginal costs of smoking to society to a point where it exceeds that marginal benefit to society. This is an example of:

b. a single paragraph.

a paragraph is a series of sentences that are organized and make sense, and are all related to a single topic . almost every piece of writing you do that is longer than a few sentences should be organized into paragraphs. this is because paragraphs show a reader where the subdivisions of an essay begin and end, and thus the reader see the organization of the essay into subjects in order to be able to understand its main points.

answer; the correct answer is (direct foreign investment);

i think the answer to your question is b. directive