The table shows how much money a grocery store receives for selling different amounts of asparagus.

ASPARAGUS SALES
NUMBER OF POUNDS
TOTAL SALES
4 lb=
$10
6 lb=
$15
8 lb=
$20
10 lb=
?
12 lb=
?

If the unit rate is constant what are the total sales for 12 pounds of asparagus?
A. $32.50
B. $25.00
C. $22.50