"How do you come to be so certain of all this, Doctor?"(Hovstad) a
Hovstad is a journalist and wants to be sure of his facts
b
Hovstad will print anything to sell his paper
c
Hovstad is a journalist who does not want to print anything that is unpopular
d
Hovstad doesn't really care if what the Dr. alleges is true but he thinks it looks good if he asks

b . Hovstad will print anything to sell his paper

Explanation:

In the book, "An Enemy of the People " by Henrik Ibsen, Dr. Stockmann alleges that the baths in the town are unsanitary and polluted to which Hovstad inquires as to how he came up with his information.

Hovstad was the Editor of the "People's Messenger" newspaper and the truth was that Hovstad did not really care for the source of the information. He only cared about if he could sell the story such that it would sell more papers for him and increase the circulation of his newspaper.