Consider the following statements about concrete sleepers. 1. They improve the track modulus. 2. They have good scrap value. 3. They render transportation easy. 4. They maintain the gauge quite satisfactorily. Of these statements A. 1 and 2 are correct B. 2 and 3 are correct C. 3 and 4 are correct D. 1 and 4 are correct

The correct answer is D. 1 and 4 are correct.

Statement 1: Concrete sleepers improve the track modulus.

This is true because concrete sleepers are more rigid than wooden sleepers. This means that they can withstand more weight and vibration, which helps to keep the track in good condition.

Statement 2: Concrete sleepers have good scrap value.

This is not necessarily true. Concrete sleepers can be recycled, but they may not have as high a scrap value as wooden sleepers.

Statement 3: Concrete sleepers render transportation easy.

This is not necessarily true. Concrete sleepers are heavier than wooden sleepers, so they may be more difficult to transport.

Statement 4: Concrete sleepers maintain the gauge quite satisfactorily.

This is true because concrete sleepers are more stable than wooden sleepers. This means that they are less likely to move out of alignment, which helps to keep the track in good condition.