The landing and takeoff of the air craft is made against the direction of wind. In no case the centre line of the runway should make an angle with the wind direction exceeding A. 10° B. 20° C. 30° D. 40°

The correct answer is $\boxed{\text{C}}$, 30°.

The landing and takeoff of an aircraft is made against the direction of the wind. This is because the wind provides a tailwind, which helps to increase the aircraft’s speed and lift. A tailwind can also help to reduce the aircraft’s landing distance.

The centre line of the runway should make an angle with the wind direction that is as close to 180° as possible. This will maximize the tailwind and minimize the crosswind. However, there is a limit to how close the centre line can be to 180°. If the centre line is too close to 180°, the aircraft may be at risk of hitting the end of the runway.

The maximum angle between the centre line of the runway and the wind direction is 30°. This is because, at an angle