Delta PDA Distributors Has an Investment in Accounts Receivable of $2,750,000

Delta PDA Distributors has an investment in accounts receivable of $2,750,000. Daily credit sales are $118,280. If 30% of Delta's credit customers receive a discount by paying within 10 days and the remainder of Delta's customers pay in 40 days, what is the Average collection period that Delta maintains?

A) 31 days
B) 40 days
C) 37 days
D) 19 days