Correct Answer:
C. Hazrat Arqam RA
The Prophet Muhammad (PBUH) began his secret preaching of Islam from the house of Hazrat Arqam RA. This house, known as Dar al-Arqam, was a safe and discreet location where early Muslims could gather, learn about Islam, and pray away from the persecution of the Quraish in Mecca. Therefore, the correct option is C: Hazrat Arqam RA.
- A: Hazrat Abu Bakr RA, B: Hazrat Usman RA, and D: Hazrat Umar RA were prominent companions, but the initial secret gatherings for preaching and instruction took place at Hazrat Arqam's residence.