Correct answer: A. Rowlatt Act
Explanation: The direct answer is option A, the Rowlatt Act. The Jallianwala Bagh massacre took place at Amritsar in 1919, when people had gathered in a period of opposition to the Rowlatt Act and related colonial repression. Step by step: connect Jallianwala Bagh with Amritsar; connect the event with 1919; then connect the protest atmosphere with the Rowlatt Act, which allowed harsh measures and detention without ordinary legal safeguards. Option A is correct. Option B, Charter Act, is wrong because Charter Acts dealt with the administration and trading arrangements of the East India Company at different earlier times, not this 1919 protest. Option C, Regulating Act, is wrong because it was an eighteenth-century measure concerning Company administration. Option D, Pitt’s India Act, is wrong because it was an eighteenth-century law creating stronger British government control over Company affairs. Memory cue: 1919, Amritsar, Jallianwala Bagh and Rowlatt Act belong together.