On which part of a "classic neuron" is the action potential initiated?

The classic neuron is referred to a nerve cell. It is divided into three regions, cell body axon and axon terminal. The cell body is a disc like structure having many projections, known as dendrites. The cell body is attached to a long thin extension called axon. Axon's one side is connected to cell body and on the other side it has axon tail, which also possess dendrites. The axon is covered with an insulating covering called myelin sheath.

At the junction of cell body and the axon, a pointed unmyelinated axon hillock is present. It is cone shaped, it is the spike initiation zone and the action potential is generated here.  

So, the correct answer is axon hillock.

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.