A client hired you to file an individual tax return. The client is a divorced single custodial parent with two children. The client claims they are entitled to the dependency deduction for the children. The ex-spouse of your client contends it is their right to claim the dependency deduction for the children on their tax returns. Explain in detail which one has the right to claim the dependency deduction for the children relying on the applicable income tax laws. Communicate the findings to both parties and provide support for the decision based on applicable tax laws. Explain why it is more advantageous to elect joint filing status as a married couple rather than separate filing status. Describe in detail the election of head of the household filing status.