Hillary makes two transactions while at the mall: • She returns an item to get $15 back at one store. • She buys an item for $15 at another store. Which is a correct description of the two quantities that represent these transactions? A The quantities have the same magnitude, but different signs. B The quantities have the same sign, but different magnitudes. C The quantities have different magnitudes and different signs. D The quantities have both the same magnitude and the same sign.