How can the mechanical advantage of a lever be increased?
a.
by applying the force farther from the fulcrum
b.
by making the lever shorter
c.
by moving the fulcrum away from the load
d.
by applying a larger force

The answer is; A

The force or weight and distance on both sides of the fulcrum is given by the following ratio;

MA = Fb/Fa = a/b (MA = Mechanical Advantage)

The greater the distance from the fulcrum on which force is applied to lift a load on the other side of the fulcrum,  the less the effort required.

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant.