The Haas Corp., a calendar year S corporation, has two equal shareholders. For the year ended December 31, year 6, Haas had net income of $60,000, which included $50,000 from operations and $10,000 from investment interest income. There were no other transactions that year. Each shareholder's basis in the stock of Haas will increase by:

a. $50,000

b. $30,000

c. $25,000

d. $0