Able, Inc., Betty, Inc and Cobra, Inc. formed a general partnership. Able has a $35\%$ interest, Betty has a $15\%$ interest and Cobra has a $50\%$ interest. Able has a September $30$ year$-$end, Betty has a calendar year end and Cobra has a June $30$ year$-$end. Explain the process that you should use to determine the year$-$end for the general partnership and what other options that may be available.