At the beginning of the period, assets were $200,000 and liabilities were $120,000. At the end of the period, assets were $300,000 and liabilities were $160,000. During the period, the owner withdrew $10,000 for personal use and made additional investments of $50,000. The amount of net income or net loss for the period was...?

A. Net income of $20,000

B. Net income of $40,000

C. Net income of $60,000

D. Net income of $20,000

E. Net loss of $40,000