A survey determined that 5/17 of the seventh grade students at Mills Middle School preferred round chocolate candies to hard candy. When Jennifer duplicated the survey, 4/17 of the students changed their preference from chocolate candy to hard candy.

What fraction of the students in the second survey preferred round chocolate candy?

A. 9/17

B. 20/289

C. 9/34

D. 1/17

C. 9/34