Step 1: Read the question.
We must name the leader called the Grand Old Man of India.
Step 2: Recall the title holder.
The title belongs to Dadabhai Naoroji, an early Congress leader.
Step 3: Recall why he earned it.
He served Indian politics for decades, was thrice Congress President, the first Indian in the British Parliament, and gave the Drain of Wealth theory.
Step 4: Rule out Gokhale.
Gopal Krishna Gokhale was Gandhi's political mentor but did not hold this title.
Step 5: Rule out Hume and Ranade.
A. O. Hume founded the Congress as a British administrator, and M. G. Ranade was a social reformer and judge, neither carrying this title.
Step 6: State the answer.
The Grand Old Man of India is Dadabhai Naoroji, option A.
\[ \boxed{\text{Dadabhai Naoroji}} \]