Task: Question Answering
Input (English): Problem: a father said to his son, ` ` i was as old as you are at the present at the time of your birth ' '. if the father ' s age is 52 years now, the son ' s age 5 years back was :
Options: a. a. 14, b. b. 67, c. c. 56, d. d. 21, e. e. 34
Output (English): d