Erica wants to buy a new dishwasher that costs $500. She has already saved $100. She earns $1,200 a month and her total monthly expenses come to $1,000. Erica is going to put all of her extra money each month into her savings account for the dishwasher. Assuming her expenses stay the same, how long will it take Erica to save enough money for the dishwasher?
A
three months
B
two months
C
five months
D
one month