Multiple Choice Question Which of the following tax activities must be completed by September 15? Decide if you can defer income to the following year. If you expect a refund, file your return for the provious year. File for an extension on your federal tax return. File your federal tax return. Pay the third installment of estimated taxes. Check to make sure your received all forms to complete your tax return. Pay the second installment of estimated taxes. Determine if vou should make estimated pryments for the next year. Need help? Review these concept resources. Resed Atout the Concept