A crumpled paper and a feather are dropped from the top of a building at the same time. Neglecting the air resistance, which one of them would reach the ground first?

The correct option is C Both would reach at the same time.
The Earth's gravitational pull causes a freely falling object near the surface to accelerate at a constant rate. The acceleration caused due to the Earth's gravity is independent of the object's mass. Hence, objects that are let to fall from the same height at the same time, all would reach the ground simultaneously, neglecting the air resistance. So, the crumpled paper and the feather would hit the ground at the same time.