What is the Newton-Raphson method used for?

I - Finding approximations of the roots of a real function of real variable continuous in a closed interval and derivable in an open interval.
II - Finding the maximum or minimum of a function.
III - Solving optimization problems.
IV - Finding the intersection of two functions.
a) I and II are correct.
b) I, II, and III are correct.
c) II and III are correct.
d) I, III, and IV are correct.