Choose the correct passive voice: They agreed to sign the contract.

The correct answer is - ক) They agreed that the contract should be signed.

- Active: They agreed to sign the contract.
- Passive: They agreed that the contract should be signed.

• Agree/ be anxious/arrange/determine/ be determined/ decide/demand + infinitive + object যুক্ত Active voice কে passive করার নিয়ম:
- প্রদত্ত Active voice এর subject ও verb বসে।
- that বসে।
- infinitive এর পরের Object (direct object) বসে।
- should be বসে।
- infinitive এর পরের verb এর past participle বসে।

• More examples:
- Active: She decided to repair the car.
- Passive: She decided that the car should be repaired.

বাকি অপশনগুলোর ব্যাখ্যা:
খ) They were agreed to sign the contract.
- বাক্যটি ভুল, কারণ "agree" সাধারণত এমনভাবে passive হয় না। "They agreed" ঠিক আছে, কিন্তু "They were agreed" নয়।

গ) The contract was agreed by them to sign.
- ভুল গঠন।

ঘ) The contract is agreed to be signed by them.
- মূল বাক্যটি past tense-এ ছিল ("agreed"), এখানে present tense ("is agreed") ব্যবহার করা হয়েছে।

Source:
1. A Passage to the English Language by SM Zakir Hussain.
2. Advanced Learner's Communicative English Grammar and Composition by Chowdhury and Hossain.