Detailed Solution:
The correct answer is “Both (A) and (R) are true, but (R) is not the correct explanation of (A)”.
The Muslim League initially accepted the Cabinet Mission Plan (May 16, 1946), which proposed a decentralized federal government for India with autonomy for the provinces.
However, in July 1946, , the Muslim League withdrew its acceptance of the plan because it did not meet their demands for a separate Muslim state.
The Muslim League initially boycotted the interim government formed in 2 September 1946. However, on October 26, 1946, five Muslim League members joined the interim government after a request from Lord Wavell.