Which of the following statements are true regarding functions? Check all that apply. O A. The vertical line test may be used to determine whether a relation is a function. OB. A sequence is a function whose domain is the set of rational numbers. C. The horizontal line test may be used to determine whether a function is one-to-one. D. A function is a relation in which multiple values of the input variable are paired with at least one of the output variable.​