Skysong, Inc. had a transaction that caused a $4100 increase in both assets and liabilities. This transaction could have been a(n)___________
a.investment of $4100 cash in the business by the stockholders.
b.repayment of a $4100 bank loan.
c.purchase of office equipment for $4100 cash.
d.purchase of office equipment for $9840, paying $5740 cash and issuing a note payable for the balance.