Why is the product of two rational numbers always rational? select from the drop-down menus to correctly complete the proof. let ab and cd represent two rational numbers. this means a, b, c, and d are , and b and d are not 0. the product of the numbers is acbd , where bd is not 0. both ac and bd are , and bd is not 0. because acbd is the ratio of two , the product is a rational number.