Mahesh Godavarti

I just figured out the correct answer to this question.

The corresponding reaction force is the body's gravitational force on the Earth which is in the opposite direction.

Remember that the gravitational force is bi-directional. If the Earth is pulling on your body, your body is pulling on the Earth at the same time.

Mahesh Godavarti

Your weight is the result of you standing on the ground while the earth is pulling down on you. The reaction force is the upward force the ground is acting on you to keep you motionless. If there was no upward force then you would be accelerating downwards.