JEE Main · 2021 · 20 Jul 2021 · Shift 1 · Gravitation

At the start the passenger rests on Earth and weighs $100\times 10=1000$ N; at the end the passenger rests on Mars and weighs $100\times 4=400$ N. In between, the pulls of the two planets act in opposite directions and the field strength falls off with distance, so the weight decreases smoothly, becomes exactly zero at the neutral point where the two pulls cancel, and then grows again as Mars is approached. Weight is the magnitude of the gravitational force, so it can never take a negative value. The curve that fits is the one that leaves $1000$ N, falls to touch zero once at an intermediate time, and then rises to $400$ N.