We need to select all the functions from the options that have a period of 2π.
If a function has period P, the function f(x) repeats its values every time x is a multiple of P.
Thus, by analyzing the graph of periodic functions, we can determine their period.
Observe the graphs of the following functions:
Notice that the functions y = tan x and y = cot x have period π.
And the functions y = csc x and y = sec x have period 2π.
Therefore, the functions that have period 2π are:
A. y = csc x
B. y = sec x