Frank's Oil Supply Has a Cash Balance of $27 and a Short-Term

Frank's Oil Supply has a cash balance of $27 and a short-term loan balance of $50 at the beginning of quarter one. The net cash inflow for the first quarter is $68 and for the second quarter there is a net cash outflow of $23. All cash shortfalls are funded with short-term debt. The firm pays 2 percent of its prior quarter's ending loan balance as interest each quarter. The minimum cash balance is $15. What is the short-term loan balance at the end of the first quarter?

A) $0
B) $13
C) $15
D) $17
E) $18