Given the graph below, which of the following statements is true?
a. the graph represents a one-to-one function because every x-value is paired with only one y-value.
b. the graph represents a one-to-one function because it is defined for all x-values.
c. the graph does not represent a one-to-one function because it does not pass through the origin.
d. the graph does not represent a one-to-one function because the y-values between 0 and 2 are paired with multiple x-values.