Answer: Option C.
9Z-20 11A-18 13Y-16 15B-14 ?
In this , first number of each Pair is increasing by 2 and the last number is decreasing by 2such as
9_ -20 , 11_-18 , 13_-16 15_-14 , so that next arrangement will be
15+2_- 14-2=> 17_-12
two series are appear as alternatively with alphabetical series and reverse alphabetical series, Such as
Z , A , Y , B Therefore, next letter will be X. Combining both numeric and alphabetical series the next pair will be = 17X-12