The average of 22 number is 52. The average of the first 8 numbers is 48 and the average of next 11 number is 54 the 20^th number is 7 less than the 21^st number and 21^st number is 4 more than 22^nd number. What is the average of the 20^th and 22^nd number?

A. 52

B. 52.5

C. 53

D. 53.5

Answer: Option D