Detailed Explanation:

The Ghadr Party was a revolutionary association of Indians with headquarters at San Francisco, California, formed in 1913.

Founded by Lala Har Dayal and Sohan Singh Bhakna, it aimed to overthrow British colonial rule through armed revolution, drawing support mainly from Indian immigrants (Sikhs, Hindus, Muslims) in North America.

✅ Option 1 – Correct: Accurately identifies the Ghadr as a revolutionary association headquartered in San Francisco.
❌ Option 2 – Incorrect: Singapore was not the headquarters; it was San Francisco.
❌ Option 3 – Incorrect: Berlin was associated with other revolutionary groups like the Berlin Committee, not Ghadr.
❌ Option 4 – Incorrect: Ghadr was not a communist movement, and Tashkent was not its headquarters.