Answer:
Option C. 
Explanation:
A bill from Acme Supply Company is marked "3/15, net 30."
This means if the bill is paid within 15 days, there is a 3% discount, otherwise a total amount is due within 30 days.
The amount of the bill = $178.95
After 3% discount = 178.95 - (3% × 178.95)
 = 178.95 - 5.37
 = $173.58 
Within 15 days you should tender $173.58.
Option C. is the answer.