Which description compares the vertical asymptote(s) of function a and function b correctly?

function a: f(x)= 1/ x+4

function b

both functions have a vertical asymptote at x=−4 .

function a has a vertical asymptote at x = 1.
function b has a vertical asymptote at x = 3.

function a has a vertical asymptote at x = 4.
function b has a vertical asymptote at x = 2.

function a has a vertical asymptote at x=−4x=−4 .
function b has a vertical asymptote at x = 2.