A suit can be brought in a federal court if it involves

a. a question under the Constitution, a treaty, or a federal law

b. citizens of different states, a foreign country and a U.S citizen, or a foreign citizen and an American citizen, and the amount in controversy is more than $75,000

c. either a or b

d. none of the above

Ace Corporation, which is based in Texas, advertises on the Web. A court in Illinois would be most likely to exercise jurisdiction over Ace if Ace

a. conducted substantial business with Illinois residents at its Web site

b. interacted with any Illinois resident through its Web site

c. only advertised passively at its Web site

d. all of the above