XYZ Partnership has the following partners: Thomas, who holds a 30% interest. Lori, who holds a 25% interest. Quality, Inc., a corporation that holds a 45% interest. Thomas and Lori are calendar-year taxpayers. Quality, Inc. uses a fiscal year that ends on October 31. On what day does XYZ's tax year end?

A: January 31.

B: April 15.

C: October 31.

D: December 31.