The correct option is C.
In physics, the gravitational law makes us to understand that gravity change with altitude. The higher the altitude, the more the gravity one will experiences. Change in altitude also produce change in weight but all these changes are not really significant. Therefore, there will be no significant difference between weighing metals at different altitude, this is because the effect of gravity on them will be the same.
An object in motion will remain in motion unless an outside force stops is.
