Stahl Consulting started the year with total assets of $60,000 and total liabilities of $15,000. During the year, the business...

Stahl Consulting started the year with total assets of $60,000 and total liabilities of $15,000. During the year, the business recorded $48,000 in catering revenues and $30,000 in expenses. Stahl made an additional investment of $9,000 and withdrew cash of $15,000 during the year. Owner's equity changed by what amount from the beginning of the year to the end of the year?

$9,000

$12,000

$45,000

$3,000