Sally and Eric Are the Only People in an Economy

Multiple Choice

Sally and Eric are the only people in an economy.Sally buys 3 bottles of water when the price is $2 a bottle and 4 bottles of water when the price is $1 a bottle.Eric buys 10 bottles of water when the price is $0.50 a bottle and 5 bottles of water when the price is $1 a bottle.In the market for water,the quantity demanded

A) increases as the price rises.
B) is 4 bottles at a price of $1 a bottle.
C) increases as the price falls.
D) is 8 bottles at a price of $2 a bottle.
E) is 15 bottles at a price of $0.50 a bottle.