For Partnership Tax Years Ending After December 31, 2015, When

For partnership tax years ending after December 31, 2015, when must a partnership file its return?

A) By the 15^th day of the 3^rd month after the partnership's tax year end.
B) By the 5^th month after the original due date if an extension is filed.
C) By the 15^th day of the 4^th month after the partnership's tax year end.
D) By the 15^th day of the 3^rd month after the partnership's tax year end and by the 5^th month after the original due date if an extension is filed.
E) By the 5^th month after the original due date if an extension is filed and by the 15^th day of the 4^th month after the partnership's tax year end.