Which of the following sentences is correct?

The correct answer is Option (4) → After the potholes were filled, the road to our college became much smoother than before.

“Much”, not “very”, before a comparative:

• A comparative is the -er form of an adjective, such as smoother or taller.
• To make a comparative stronger, we put much before it. So “much smoother than before” is correct.

Why the Other Options are Incorrect?

Option 1: After the potholes were filled, the road to our college became very smoother than before. — Incorrect. “Very” is used before a plain adjective (very smooth). It is not used before a comparative like “smoother”.

Option 2: After the potholes were filled, the road to our college became more smoother than before. — Incorrect. “Smoother” is already a comparative. Adding “more” makes a double comparative.

Option 3: After the potholes were filled, the road to our college became much more smoother than before. — Incorrect. “Much” is right, but “more smoother” is still a double comparative.