Which one of the following sentences contains an unnecessary colon?
a. carlos has three goals in life: to graduate from college, own his own home, and work in the computer industry.
b. i wrote my shopping list and put: milk, soup, chicken, and ice cream on it.
c. here's the question on all of our minds: will our team be able to defeat their arch rivals tonight?
d. she wants one thing: a new job.