Answer : 3. "Baldev Singh"
Explanation :

The Cabinet of the Interim Government of India is composed of the following members-

1. Agriculture and Food: Rajendra Prasad (INC)

2. Commerce: Ibrahim Ismail Chandrigar (ML)

3. Defence: Baldev Singh (INC)

4. Finance: Liaqat Ali Khan (ML)

5. Education and Arts: C Rajagopalachari (INC)

6. Health: Ghazanfar Ali Khan (ML)

7. Labour: Jagjivan Ram (INC)

8. Law: Jogendra Nath Mandal (ML)

9. Railways & Communications, Posts & Air: Abdul Rab Nistar (ML)

10. Work, Mine and Power: CH Bhabha (INC)

11. Commander-in-Chief: Sir Claude Auchinleck

12. Home Affairs, Information and Broadcasting: Sardar Vallabhbhai Patel (INC)