An S corporation is owned equally by A and B, whose respective stock bases at the beginning of the year are $12,000 and $13,000. During the year, the corporation had $100,000 in ordinary business income and $5,000 in tax-exempt income. The corporation distributed $50,000 to each shareholder for the year. What is owner B's stock basis at year end? A. $15,500 B. $15,000 C. $13,000 D. $10,500