If the value of owner's equity is initially $10,000, calculate the value of owner's equity after the following transactions: cash revenues $9,000, prepay rent $3,000, pay bank loan principal $2,000, pay maintenance fees $4,000 and buy a computer on account for $1,000. Select one: a. $13,000 b. $15,000 c. $9,000 d. $11,000