Below are the 2014 and 2015 year-end balance sheets for Tran Enterprises:

Assets: 2015 2014
Cash $200,000 $170,000
Accounts receivable 864,000 700,000
Inventories 2,000,000 1,400,000
Total current assets $3,064,000 $2,270,000
Net fixed assets 6,000,000 5,600,000
Total assets $9,064,000 $7,870,000

Liabilities and equity:
Accounts payable $1,400,000 $1,090,000
Notes payable to bank 1,600,000 1,800,000
Total current liabilities $3,000,000 $2,890,000
Long-term debt 2,400,000 2,400,000
Common stock 3,000,000 2,000,000
Retained earnings 664,000 580,000
Total common equity $3,664,000 $2,580,000
Total liabilities and equity $9,064,000 $7,870,000

The firm has never paid a dividend on its common stock, and it issued $2,400,000 of 10-year, non-callable, long-term debt in 2014. As of the end of 2015, none of the principal on this debt had been repaid. Assume that the company's sales in 2014 and 2015 were the same. Which of the following statements must be CORRECT?

a. The firm increased its short-term bank debt in 2015.
b. The firm repurchased some common stock in 2015.
c. The firm had negative net income in 2015.
d. The firm issued long-term debt in 2015.
e. The firm issued new common stock in 2015.