It is high time he (change) his bad habits.

Explanation: - উল্লেখিত প্রশ্নের সঠিক উত্তর হচ্ছে changed.

• It is time/ It is high time এরপর যদি subject থাকে তাহলে verb টি past tense এ হয়।
Example:
It is high time we left the place.
It is high time we stopped corruption.
It is high time he changed his bad habits.

• It is time/It is high time এরপর যদি subject না থাকে তবে to + verb হয়।
Example: It is high time to stop corruption.

Source: Applied Englishn Grammar and Composition, P.C. DAS.