8. which force is responsible for pulling a plate downward into the asthenosphere?
o a. gravity
o b. buoyancy
o c. air pressure
d. magnetism

Gravity

Explanation:

Gravity is the force that attracts a body towards the centre of the earth or towards other physical bodies which contain mass.

Buoyancy is the ability or tendency of an object to float in a fluid. According to Archimedes' Principle ,  the buoyant force on a submerged object is equal to the force of gravity on the liquid displaced by the object.

Air pressure is defined as the force exerted per unit area exerted against a surface by the weight of the air above that surface.

Magnetism is a physical phenomena which arises from the force caused by magnets , which are objects that produce fields that attract or repel other objects.

Thus gravity is responsible for pulling a plate downward into the asthenosphere.