Trouble with the concept

I think I've narrowed this down, but I'm not sure yet:

You're hired to conduct a study to find out which of two brands of diet cola college students tend to rate more highly based on taste. In your study, 25 students on your campus volunteer and are given a blind taste test. They taste and rate one brand, chew a cracker in between, and then taste and rate the other. Which of the two brands is tasted first is randomly assigned for each student. The ratings are given on a scale of 1 (awful) to 10 (delicious). Which type of test would be an appropriate way to compare the ratings given to the two sodas?
a. paired (matched) t–test
b. two-sample t-test comparing ratings for the two brands of diet cola.
c. test if slope of regression line equals zero
d. chi-square test (testing independence of ratings and brands of diet cola)

I'm pretty sure that it's not b or c...but other than that I'm lost. A and D both seem like they could work. Please help!
Since these data are of the categorical type, my first guess is that your instructor wanted d. You are correct in thinking b. and c. are no good. In fact, they are exactly the same test.