Unbalanced forces A.
maintain the constant motion of an object.

B.
cause the motion of an object to change.

C.
can change an object's speed but not direction.

D.
make an object move opposite the applied force.

the answer is B.

Explanation:

unbalanced force means unequal force when two personas are pushing an object on opposite sides, more force than the other. Unbalanced force DOES NOT mean 'constant'. Balanced forces are what's constant. It can cause a change in motion (in general), meaning that it can change an objects speed AND direction, not just speed, or moving it to the opposite side.

in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.

increase masses, decrease separation