Which of the following transactions would cause a firms working capital to increase?

a. Pay out $2 million cash dividend.

b. Receive $2,500 from a customer who pays a bill resulting from a previous sale.

c. Pay $5,000 previously owed to one of its suppliers.

d. Borrow $1 million long-term and invest the proceeds in inventory.

e. Borrow $1 million short-term and invest the proceeds in inventory.

f. Sell $5 million of marketable securities for cash.