Concept:The assertion states that national progress depends on unity among different social and political groups, and political parties must preserve this unity even during competitive elections. The correct developments are those that either promote or break this unity, thereby proving the point.
Explanation:Statement (a) shows deliberate effort to unite Hindus and Muslims during the Rowlatt Satyagraha. This supports the assertion that unity is essential for progress.
Statement (b) describes the Muslim League beginning to view Muslims as a separate nation from the late 1930s. This divides unity, so it does not support the assertion; rather, it contradicts the idea of unity.
Statement (c) mentions the Congress rejecting the League's proposal to form a joint government in the United Provinces in 1937. This refusal broke political unity and harmed the collective struggle, illustrating the importance of maintaining unity as warned in the assertion.
Thus, the developments that directly attest to the assertion are (a) and (c).
Answer:C. (c) and (a)