Hello, I am preparing for the ACT and stumbled upon a question that I don't understand.

It says, "If tan x and cot x are defined, what is the value of (tan2x)(cot2x)?" (the 2 representing a square)

The possible choices are:

a) 0

b) 1

c) sin2 x -1 / cos2 x

d) tan2x + sec2x

e) (sec2x + 1)(csc2x + 1)

Of course, I don't need the answer; I need an explanation. Any help is appreciated!