Answer
A) As we move to higher altitudes, the force of gravity on us decreases.
Step-by-step explanation
Gravitational force is the force of attraction between two bodies that given masses.
Gravitational force of the earth exists between the earth and other objects close to it.
This force is inversely to the square of distance between them. This means as the distance between the earth and the object increases, the gravity decreases.
∴ the correct answer is: A) As we move to higher altitudes, the force of gravity on us decreases.