Number Series - Verbal and Reasoning

Directions to SolveLook carefully for the pattern, and then choose which pair of numbers comes next.
Q1:

9 11 33 13 15 33 17

A 19 33

B 33 35

C 33 19

D 15 33

E 19 21

ANS:A - 19 33

In 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.