Assertion (A): The Congress Ministries in all the provinces resigned in the year 1939. Reason (R): The Congress did not
In Assertion-Reason, check both parts calmly. Here, the combination that fits is Both (A) and (R) are individually true and.... In Second World War, this is how Assertion and Reason are linked. If you check Assertion first, then Reason, then the link, the answer becomes clear. That is the simple way to do it.
Ref: [IAS (Pre) 2008] | Bipan Chandra, India's Struggle for Independence, and NCERT History textbooks discuss Second World War and explain the events, leaders and movements that support the correct answer for this question.