Read the passage and answer the question:

The Sino-Indian conflict affected the opposition as well. This and the growing rift between China and the Soviet Union created irreconcilable differences within the Communist Party of India (CPI). The pro-USSR faction remained within the CPI and moved towards closer ties with the Congress. The other faction was for sometime closer to China and was against any ties with the Congress. The party split in 1964 and the leaders of the latter faction formed the Communist Party of India (Marxist) (CPI-M). In the wake of the China war, many leaders of what became CPI (M) were arrested for being pro-China. The war with China alerted the Indian leadership to the volatile situation in the Northeast region. Apart from being isolated and extremely underdeveloped, this region also presented India with the challenge of national integration and political unity. The process of its reorganisation began soon after the China war. Nagaland was granted statehood; Manipur and Tripura, though Union Territories, were given the right to elect their own legislative assemblies.

What happened to the leaders of the Communist Party of India (Marxist) who were pro-China after the China War?

They were arrested.

The correct answer is Option 3 - They were arrested.

Many leaders of CPI (M) who were pro-China after the China War were arrested for being pro-China.

As per the passage:

The Sino-Indian conflict affected the opposition as well. This and the growing rift between China and the Soviet Union created irreconcilable differences within the Communist Party of India (CPI). The pro-USSR faction remained within the CPI and moved towards closer ties with the Congress. The other faction was for sometime closer to China and was against any ties with the Congress. The party split in 1964 and the leaders of the latter faction formed the Communist Party of India (Marxist) (CPI-M). In the wake of the China war, many leaders of what became CPI (M) were arrested for being pro-China.