Jordan,Inc

Jordan,Inc.,Bird,Inc.,Ewing,Inc.,and Barkley,Inc.formed Nothing-But-Net Partnership on June 1ˢᵗ,20X9.Now,Nothing-But-Net must adopt its required tax year-end.The partners' year-ends,profits interests,and capital interests are reflected in the table below.Given this information,what tax year-end must Nothing-But-Net use and what rule requires this year-end?
 
$\begin{array} { l c c c } & \text { Nothing-But-Net Partrership } & \\& \text { Year-End } & \text { Profits } & \text { Capital } \\\text { Jordar, Inc. } & 4 / 30 & 45 \% & 25 \% \\\text { Bird, Inc. } & 9 / 30 & 25 \% & 25 \% \\\text { Ewing, Inc. } & 10 / 31 & 0 \% & 25 \% \\\text { Barkley, Irce } & 12 / 31 & 30 \% & 25 \%\end{array}$