Suppose You Earn $4,800 a Month and Spend Exactly $160

Suppose you earn $4,800 a month and spend exactly $160 in each of the 30 days. If you deposit $1, 600 into your checking account on the first day, eleventh day, and twenty-first day of the month, then your average quantity of money demanded is

A) $800.
B) $1,200.
C) $2,400.
D) $4,800.