Grapefruit Services started the year with total assets of $90,000 and total liabilities of $45,000. The company is a sole proprietorship. The revenues and the expenses for the year amounted to $120,000 and $80,000, respectively. During the year, there were no new capital contributions and the owner withdrew $50,000. What is the amount of owner's equity at the end of the year? $50,000 O $120,000 $35,000 $80,000