Which of the following is an asymptote of y is equal to secant of x ?

Since sec x = 1/cos x, vertical asymptotes occur where cos x = 0. This happens at x = π/2 + kπ, where k is any integer. The choice x = 3π/2 fits this rule, so it is an asymptote; the other listed values have nonzero cosine.

AI-written and checked against the verified answer.