O. Stahl Consulting started the year with total assets of $20,000 and total liabilities of $5,000. During the year, the business recorded $16,000 in catering revenues and $10,000 in expenses. Stahl made an additional investment of $3,000 and withdrew cash of $5,000 during the year. Owner's equity changed by what amount from the beginning of the year to the end of the year? a. $1,000 b $3,000. C. $4,000 $15,000