Assertion (A) : Lord Linlithgow described the August Movement of 1942 as the most serious rebellion since Sepoy Mutiny. Reason (R) : There was massive upsurge of the peasantry in certain areas.

The correct answer is Option 1.

Assertion (A) is true because the Quit India Movement (August Movement) of 1942 was characterized by unprecedented intensity and scale. Viceroy Lord Linlithgow, in a secret telegram to Winston Churchill, explicitly described it as "by far the most serious rebellion since that of 1857," acknowledging the threat it posed to British hegemony.

Reason (R) is true and provides the correct explanation for the Assertion. The movement saw a massive upsurge of the peasantry, particularly in Bihar, Eastern U.P., Bengal, and Maharashtra. Peasants engaged in sabotage, attacked symbols of state authority (police stations, railways), and established parallel governments (Sarkars). This widespread rural participation transformed a political protest into a violent, decentralized rebellion that paralyzed the colonial administration, justifying Linlithgow's comparison to the 1857 Mutiny.