The number of sales per month ranged from 80 to 160.
How many sales are represented by each dollar sign?

Number of Sales per Month

Jan- $$$ (5 dollar signs)
Feb- $$$$ (7 dollar signs)
Mar-$$ (4 dollar signs)
Apr- $$$$ (8 dollar signs)

A) 10
B) 15
C) 20
D) 30