9 11 33 13 15 33 17 , 9 11 33 13 15 33 17

A. 19 33

B. 33 35

C. 33 19

D. 15 33

Correct Answer :

A. 19 33

Explanation

n this alternating repetition series, a random number, 33, is interpolated every third number into a simple addition series, in which each number increases by 2.