Explanation:

- Kartar Singh Sarabha: He was a prominent Indian revolutionary. He played a significant role in the Ghadar Conspiracy, which aimed to incite a revolt against British rule in India. His execution took place in Lahore in November 1915.

- Tantia Mama: He was a part of the Indian freedom struggle, but is not related to the Ghadar Conspiracy or executed in 1915.

- Maganbhai Patel: There is no significant historical association of him with the Ghadar Conspiracy or an execution in 1915.

- Vijay Singh Pathik: An important figure in the Indian independence movement, but not known for involvement in the Ghadar Conspiracy.

Kartar Singh Sarabha is the correct answer.