Please explain how you got the answer.

6. Carla's Computer Repair Shop started the year with total assets of $270,000 and total liabilities of $180,000. During the year, the business recorded $450,000 in computer repair revenues, $255,000 in expenses, and Carla withdrew $45,000. Disregarding income taxes, Carla's Capital balance changed by what amount from the beginning of the year to the end of the year? A) $45,000. B) $195,000. C) $90,000. D) $150,000