Number Series - Verbal and Reasoning

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

40 40 31 31 22 22 13

A 13 4

B 13 5

C 4 13

D 9 4

E 4 4

ANS:A - 13 4

This is a subtraction series with repetition. Each number repeats itself and then decreases by 9.