Step 1: Understanding the Question:
We have four leaders and four contributions. The plan is to use the surest matches first and then remove options.
Step 2: Start with the surest pair.
The Bharatiya Kranti Dal is the party of Charan Singh. So (C) goes with (IV). Option (1) gives C-III, option (2) gives C-I and option (3) gives C-II. Only option (4) has C-IV.
Step 3: Confirm with a second pair.
The railway strike of 1974 was led by George Fernandes. So (D) goes with (I). Option (4) shows D-I, which agrees.
Step 4: Check the remaining pairs.
Jayaprakash Narayan helped to found the Congress Socialist Party, so A-III. The Gujarat students protest of 1974 was backed by Morarji Desai, so B-II. Both agree with option (4).
Step 5: Why the others fail.
Each wrong option breaks at least one of the sure pairs found above. Options (1) and (2) give A-II, but JP did not found the students protest in Gujarat. Option (3) gives B-IV, but Morarji Desai did not found the BKD.
Final Answer:
All four pairs fit only option (4).
\[ \boxed{\text{Option 4}} \]