Because of violence Gandhiji called off the movement (Civil Disobedience).
And signed the pact with Viceroy Irwin, popularly known as Gandhi - Irwin pact.

Thus, option d) is correct

Reasons for Gandhi's Attendance at the Second Round Table Conference of December 1931

There were two main reasons why Mahatma Gandhi attended the Second Round Table Conference in December 1931:

1. The Arrest of Ghaffar Khan and Jawaharlal Nehru

In 1931, the British government arrested two prominent Indian leaders, Ghaffar Khan and Jawaharlal Nehru, who were leading the Indian National Congress. Gandhi believed that their arrest was unjust and that their participation in the Round Table Conference was important for India's cause. He saw it as an opportunity for them to represent the Indian viewpoint and negotiate with the British government for greater autonomy and independence.

2. Violence of Indian People Against Symbols of the British Raj

There was a lot of violence in India during this time, particularly against symbols of the British Raj such as railways and police posts. Gandhi believed that this violence was counterproductive and would only serve to strengthen the British government's resolve to maintain their hold on India. He saw the Round Table Conference as an opportunity to present a peaceful and non-violent approach to achieving independence for India.

The Signing of the Gandhi-Irwin Pact in March 1931

It is worth noting that the signing of the Gandhi-Irwin Pact in March 1931 was also a significant event that paved the way for Gandhi's attendance at the Second Round Table Conference. The pact was an agreement between Gandhi and the then Viceroy of India, Lord Irwin, which ended the Civil Disobedience Movement and secured the release of political prisoners. This gave Gandhi the confidence that the British government was willing to negotiate and that his attendance at the Round Table Conference would not be in vain.

Conclusion

In summary, Gandhi's attendance at the Second Round Table Conference of December 1931 was motivated by his desire to represent the Indian viewpoint in negotiations with the British government and to present a peaceful approach to achieving independence. The arrest of Ghaffar Khan and Jawaharlal Nehru and the violence in India against symbols of the British Raj were two key factors that led Gandhi to attend the conference. The signing of the Gandhi-Irwin Pact in March 1931 also played a significant role in paving the way for his attendance.