The correct answer is: B. sharp curve.
Wear of rails is maximum in weight of sharp curve because the wheels of the train exert more force on the rails when they are turning. This force causes the rails to wear down more quickly.
In a tangent track, the wheels of the train are not turning, so they do not exert as much force on the rails. This means that the rails do not wear down as quickly in a tangent track.
In a tunnel, the air is often moist, which can cause the rails to rust. Rust can also cause the rails to wear down more quickly.
In a coastal area, the air is often salty, which can also cause the rails to rust. Rust can also cause the rails to wear down more quickly.
However, the wear of rails is maximum in weight of sharp curve because the wheels of the train exert more force on the rails when they are turning. This force causes the rails to wear down more quickly.