To determine whether a graph of a relation is also a function Shayla declares that the y-axis is a vertical line and counts the number of times that the graph intersects the y-axis If the graph has exactly one y-intercept Shayla concludes that the graph shows a function. In all other cases, she declares that it is not a function.
Is Shayla applying the vertical line test correctly?
No, because the y-axis is a horizontal line.
No, because using the y-axis tests only whether x = 0 is mapped to multiple values.
Yes, because multiple y-intercepts represent multiple x-values being mapped to y

Question

To determine whether a graph of a relation is also a function Shayla declares that the y-axis is a vertical line and counts the number of times that the graph intersects the y-axis If the graph has exactly one y-intercept Shayla concludes that the graph shows a function. In all other cases, she declares that it is not a function. 
Is Shayla applying the vertical line test correctly?
No, because the y-axis is a horizontal line.
No, because using the y-axis tests only whether x = 0 is mapped to multiple values.
Yes, because multiple y-intercepts represent multiple x-values being mapped to y