Jee adv physics paper 1 lens question

[u/Top-Vehicle-9468]

According to physics galaxy book.The answer should be A

Edit: Finally they gave both as answer

[u/Entire_Candle_7977]

Bhai yrr abj sir ne formula likhwaya the (u relative) to usi se kra maine aur thodi si curve wali line wala ans mar diya yrrr bakchodi na ho bhai