While he ______ dinner, the guests arrived.

• Correct Answer: ঘ) was cooking.

• While এর ঠিক পরে যে ক্রিয়া থাকে তার সাথে ing যোগ হয়।
- Example: While walking in the garden, a snake bit him.

• কিন্তু While এর পরে Subject থাকলে While এর অংশটি Past Continouns Tense হয়।
- Example: While he was walking in the garden, a snake bit him.

• Correct Answer: While he was cooking dinner, the guests arrived.

Source: Advanced Learner's Communicative English Grammar & Composition By Chowdhury & Hossain.