Option 1 -> "Fair-weather friends" is an established idiom meaning friends who are only present during good times and desert you when things get tough or when they can't benefit.
Option 2 -> "Party friends" is informal slang but not a recognized idiom, and lacks the warning connotation that the mother is expressing.
Option 3 -> Too literal and wordy; adds unnecessary judgment ("bad boys") that changes the original meaning.
Option 4 -> Contradicts the warning - "good natured friends" suggests genuine, kind friends, which is opposite to the intended meaning.
Hence, Option 1: fair-weather friends -> This idiom perfectly captures the essence of friends who only come around for their own enjoyment and benefit, not for genuine friendship, which is exactly what Sudhir's mother is warning him about -> correct