Option 1: Shyamiji Krishna Verma- Shyamiji Krishna Verma was a prominent leader of the Indian independence movement and played a crucial role in the revolutionary activities in India. However, he was not directly associated with the Gadar Movement.

Option 2: Lala Hardayal- Lala Hardayal was indeed one of the key figures in the Gadar Movement. He was a revolutionary, writer, and journalist who worked tirelessly to mobilize Indians living abroad, particularly in the United States and Canada, for the cause of Indian independence.

Option 3: Bipin Chandra Pal- Bipin Chandra Pal, also known as the "Father of Revolutionary Thoughts in India," was an influential leader during the freedom struggle. However, his contributions were mainly focused on the Swadeshi movement and he did not have a direct involvement in the Gadar Movement.

Option 4: Vishnu Ganesh Pingle- Vishnu Ganesh Pingle was a revolutionary and played a significant role in various revolutionary activities. However, his involvement in the Gadar Movement was limited, and he was not one of the central figures in the movement.

So, the correct answer is option 2, Lala Hardayal, who played an important role in