Isaac Co. sells merchandise on credit to Sonar Co in the amount of $9,600. The invoice is dated on April 15 with terms of 1/15, net 45. What is the amount of the discount and up to what date must the invoice be paid in order for the buyer to take advantage of the discount?
A) $96, April 30
B) $192, April 25
C) $80, April 30
D) $96, April 25