Feedback always occurs when

A.
the input of a system comes back to influence the output of and processes involved in that system.
B.
the output of a system comes back to influence the subsequent functioning of that system.
C.
no new raw materials are added to the system.
D.
no products or wastes are formed by the system.

the output of a system come s back to influence the subsequent functioning of that system.

explanation:

the universal gravitation equation. since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. if the mass of one of the objects is doubled, then the force of gravity between them is doubled.

rising temperatures because when water vapor in the air is cooled, it condenses. it turns back into a liquid and attaches to dust particles in the air. these very small water droplets group together to form clouds