When a Company Runs a Contest Online, It Will Measure

When a company runs a contest online, it will measure its effectiveness in a variety of ways. One such measure is the conversion rate. The conversion rate for an online contest promotion would be

A) the number of people who recommend the contest to others.
B) the number of people who comment on the contest.
C) the number of people who share the contest on their social media site.
D) the percentage of visitors who enter the contest.
E) the percentage of fans who like the contest.