This question seems to be a riddle rather than a traditional question. The riddle states that there is a snake (saap) by the river (nadi) and asks who the father (baap) of the snake's son (beta) is.
The correct answer to this riddle is option C) Pota.
Explanation:
In Hindi, "Pota" means grandson. So, in this riddle, the father of the snake's son is the grandson (pota).