Refer to the following items on the balance sheets of a firm for the years ending December 31, 2018 and 2019.
Item 2018 2019
Accounts Payable $729,500 $917,300
Long Term Debt $1,267,700 $1,093,400
Common Stock ($1 par) $2,184,000 $2,471,300
Retained Earnings $3,227,100 $3,419,800
If the firm's interest expense on its 2019 income statement was $312,920, calculate the net cash flow to the firm's creditors in 2019.
a) $312,920
b) $138,620
c) $425,920
d) $487,220