Atrue statement about mass is that:
(a.) mass is often measured with a spring scale
(b.) mass is expressed in pounds
(c.) as the force of earth's gravity on an object increases, the object's mass increases
(d.) mass is determined by comparing the mass of an object with a set of standard masses that are part of a balance

(c.) as the force of Earth's gravity on an object increases, the object's mass increases

Explanation:

Based on newton's law of gravitation "every particle of matter in the universe attracts every other particle with a force that is directly proportional to the product of the masses of the particles and inversely proportional to the square of the distance between them".

It is mathematically expressed as:

    F =

F is the gravitational force on either particle

m₁ and m₂ are the masses

r is the distance between particles

G is the universal gravitation constant.

From this expression, we see that the force of earth's gravity is directly proportional to mass.

2b2t

explanation:

2b2t