A company is considering implementing a lockbox system. There is an annual fee of $7,610 plus a transaction fee of $0.05 per payment. The average size of customer payments is $3,615, and there are 39 payments made daily on average. The company can earn an EAR of 3.81% on its cash balances. For the lockbox system to be adopted with a positive NPV, by how many days should the average collection time be reduced at a minimum? Fractional answers are OK. (Assume 365 days in a year.)

A) 1.55

B) 1.59

C) 1.63

D) 1.67

E) 1.71