What is the objective of the experiment described in the text?

I- To study the influence of various conditions on the amount of electricity generated.
II- To discover the direction of the current flow induced by a change in the magnetic field.
III- To calculate the force acting on charges in motion.
IV- To describe the process of electromagnetic induction.
a) Only I and II are correct.
b) Only II and IV are correct.
c) Only I, II, and IV are correct.
d) Only III and IV are correct.