Step 1: Understanding the presidency of the Indian National Congress.
Subhash Chandra Bose became the President of the Indian National Congress in 1938 and 1939. He was elected in 1938 at the Haripura session and again in 1939 at the Tripuri session. His presidency is marked by his radical views on achieving Indian independence.
Step 2: Analyzing the options.
(A) Jawaharlal Nehru: Nehru was a prominent leader of the INC but did not serve as the President in 1938 and 1939.
(B) Maulana Azad: Maulana Azad was the President of the Congress from 1940 to 1946, not in 1938 and 1939.
(C) Subhash Chandra Bose: Correct. Bose was elected as the President of the INC in 1938 and 1939.
(D) Rajendra Prasad: Rajendra Prasad was an influential leader but did not serve as the President of the INC during these years.
Step 3: Conclusion.
The correct answer is (C) Subhash Chandra Bose, as he was the President of the Indian National Congress in 1938 and 1939.