Of 100,000 Customers Who Were Active in 2005, 60,000 Are

Multiple Choice

Of 100,000 customers who were active in 2005, 60,000 are still active in 2006. The maverage retention rate is

A) It can't be determined since the initial 100,000 have not been segmented into cohorts.
B) 40%
C) 1 × .9 × .6 = 54%
D) 60%
E) None of the above