Siri and Amaliyah are both calendar$-$year taxpayers, and each own a $15\%$ interest in ABC, Fine Food Purveyors. ABC is a partnership. DEF, Inc., owns $70\%$ of ABC. DEF uses a fiscal year that ends on March $30$th$.$ The ABC partnership has not established a business purpose for using a particular tax year, nor has it made a fiscal year election. On what date will the partnership's required tax year end?

March $15$th$.$

March $30$th$.$

April $15$th$.$

May $31$st$.$