Step 1: Historical fact.
The Communist Party of India (CPI) was founded in 1920 in Tashkent (now in Uzbekistan) by M.N. Roy and other Indian revolutionaries.
Step 2: Options analysis.
(A) Lucknow: Incorrect.
(B) Berlin: Incorrect.
(C) Delhi: Incorrect.
(D) Tashkent: Correct — the CPI was founded in Tashkent.
Step 3: Conclusion.
The Communist Party of India was established in Tashkent.