Correct option is D
The correct idiom to fill in the blank is (D) a fair-weather friend.
Explanation:
A "fair-weather friend" is someone who is only a friend when circumstances are pleasant or favorable but disappears during difficult times. (Hindi meaning: स्वार्थी मित्र)
Example: She realized that many of her so-called friends were just fair-weather friends when she lost her job.
Meanings of other options:
Option A: Birds of a feather flock together – Similar people stick together. (एक जैसे लोग साथ रहते हैं)
Option B: A friend in need is a friend indeed – True friends help in difficulties. (सच्चा मित्र वही है जो मुसीबत में काम आए)
Option C: A friend in high places – Someone with influential contacts. (ऊँचे पद वाला मित्र)
Information Booster:
A "fair-weather friend" is unreliable in tough times.