Two Brands of Bottled Water,Natural Water and Mountain Water,are Close

Two brands of bottled water,Natural Water and Mountain Water,are close substitutes.If the price of Mountain Water decreases,the fall in price

A) shifts the demand curve for Natural Water rightward.
B) shifts the demand curve for Natural Water leftward.
C) increases the demand for Mountain Water.
D) increases the price of Natural Water.
E) More information is needed to determine if the demand curve for Natural Water shifts rightward or leftward.