Question: Snax Box is a subscription service that compiles and sends its subscribers a variety of snacks that they may enjoy on a monthly basis. In 2017 they had 16,000 subscribers. In 2018, a competing company executed a successful marketing campaign that led to a decrease of subscribers for Snax Box. They ended the year with 12,000 subscribers. What was Snax Box's retention rate from 2017 to 2018?
a. 166%
b. 6.6%
c. 66%
d. 0.66%
e. The correct answer is not listed