The correct answer is option 3: Simon Commission.

The Simon Commission, also known as the Indian Statutory Commission, was appointed in 1927 by the British government to propose constitutional reforms for India. The commission was headed by Sir John Simon and consisted of six other members, all of whom were British.

The appointment of the Simon Commission was in response to the growing demand for political reforms in India. The commission was tasked with reviewing the working of the 1919 Montague-Chelmsford Reforms and making recommendations for further constitutional changes.

The Minto-Morley Reforms (option 1) refer to the Indian Councils Act of 1909, which introduced separate electorates for Muslims and increased the size of the legislative councils in India. This reform was not directly related to drafting a Dominion Status Constitution.

The Montague-Chelmsford Reforms (option 2) were introduced in 1919 and expanded the legislative councils and increased the involvement of Indians in the governance of India. While important for Indian political reform, this was not specifically aimed at drafting a Dominion Status Constitution.

The First Round Table Conference (option 4) was held in 1930-1931 and involved discussions between various Indian political leaders and representatives of the British