Which of the following statements is not true? Choose the correct answer. A. A function \( f \) is one-to-one if for any two range values \( f(u) \) and \( f(v), f(u)=f(v) \) implies that \( u= \) B. A function \( f \) is one-to-one if for any values \( a \neq b \) in the domain of \( f, f(a) \neq f(b) \). C. Every function that passes the vertical line test is one-to-one. D. Every function that passes the horizontal line test is one-to-one.

To determine which of the following statements is not true, let's analyze each statement: A. A function \( f \) is one-to-one if for any two range values \( f(u) \) and \( f(v), f(u)=f(v) \) implies that \( u= \) This statement is true. A function is one-to-one if each element in the domain maps to a unique element in the range. B. A function \( f \) is one-to-one if for any values \( a \neq b \) in the domain of \( f, f(a) \neq f(b) \) This statement is also true. A function is one-to-one if different elements in the domain map to different elements in the range. C. Every function that passes the vertical line test is one-to-one. This statement is true. A function passes the vertical line test if every vertical line intersects the graph of the function at most once. This implies that the function is one-to-one. D. Every function that passes the horizontal line test is one-to-one. This statement is not true. A function passes the horizontal line test if every horizontal line intersects the graph of the function at most once. However, this does not guarantee that the function is one-to-one. There can be functions that pass the horizontal line test but are not one-to-one. Therefore, the statement that is not true is D. Every function that passes the horizontal line test is one-to-one.