The correct answer is (d).
The boy can reach the school by facing the school and walking. This is because if he faces the school, he will be walking in the direction of the school. Even though he takes one step forward and two steps backward, he will still be moving towards the school.
Option (a) is incorrect because using an umbrella will not help the boy to walk forward. Option (b) is incorrect because a cycle is a vehicle, and the boy is not allowed to ride a vehicle to school. Option (c) is incorrect because if the boy faces home and walks, he will be walking away from the school.