Which rational numbers when multiplied by -1/2 will result in a positive rational number as the product and why? a) any negative rational number because the product of two negative rational numbers is a positive rational number b) any even rational number because the product of a rational number and an even rational number is a positive rational number c) any rational number greater than 1/2 because the product of two rational numbers takes the sign of the greater rational number d) any rational number greater than 0 because the product of a negative rational number and a positive rational number is a positivie rational number