Question

Not every straight line will pass the vertical line test. What is the only type

Answer 1

Answer: B) vertical line

A vertical line has all points with the same x coordinate, but infinitely many different y coordinates. It inherently fails the vertical line test because we can pass a single straight line through more than one point on the function curve.

Put another way, the input is a single value but there's infinitely many outputs. A function must have each input produce exactly one output. This is of course only when the input is in the domain.