What distinguishes mass from weight?

a.
mass is a measure of the amount of matter in an object, while weight is a measure of the force of gravity on the object.
b.
weight is a measure of the amount of matter in an object, while mass is a measure of the force of gravity on the object.
c.
mass is a measure of an object's inertial force, and weight is the force exerted by that object on other objects.
d.
mass and weight are synonyms and ultimately describe the same principle.