sarah, sue, and as inc. formed a partnership on may 1, 20x9 called ssas, lp. now that the partnership is formed, they must determine its appropriate year-end. sarah has a 30% profits and capital interest while sue has a 35% profits and capital interest. both sarah and sue have calendar year-ends. as inc. holds the remaining profits and capital interest in the lp, and it has a september 30 year-end. what tax year-end must ssas, lp use for 20x9 and which test or rule requires this year-end?