When considering gravity acceleration and the force of acceleration, what must be true?

a. the direction of the force and the direction of acceleration must be the same as each other.
b. the mass of the body must be the same as the acceleration of the body.
c. the direction of the force and the direction of acceleration must be opposite of each other.
d. the direction of acceleration must be perpendicular to the direction of the force.

A. The direction of the force and the direction of acceleration must be the same as each other.

Explanation:

Force can be defined as push or pull. An unbalanced force that is non-zero net force causes a body to accelerate. Newton's second law states that acceleration depends on the force.

F = m a

where m is the mass of the body and a is the acceleration.

Increase in force causes increase in acceleration. The direction of acceleration and direction of force are same.

Considering acceleration due to gravity and force of acceleration - gravitational force always acts along the line joining the centers of two bodies and so, the direction of the acceleration due to gravity also is in the same direction.

The direction of the force and the direction of acceleration must be the same as each other.

Explanation:

According to Newton's second law of motion, the force acting on an object  depends on its acceleration. Its formula is given by :

F = m a

Where,

m is the mas of an object

a is its acceleration.

i.e. force is directly proportional to the acceleration of an object. The direction of force and acceleration must be same.  

Hence, the correct option is (A) "The direction of the force and the direction of acceleration must be the same as each other".