He tried his best . ( Negative )

A He did not try a little .

B He did not stay unmoved.

C He left no stone unturned .

D He did not turn all stones .

Correct Answer: Option C

He tried his best ( সে সর্বোচ্চ চেষ্টা চালানো) এর - negative sentence হলো He left no stone unturned ( সেই চেষ্টার ত্রুটি করল না)।