Final answer:
For federal tax purposes, Kiri and Divina cannot file as married because domestic partnerships are not recognized as marriage by the IRS. As they have no dependents, the most favorable filing status for them in 2022 is Single.
Married filing separately, is the correct answer.
Step-by-step explanation:
To determine Kiri's and Divina's most favorable 2022 filing status on the federal return, we should consider the recognition of registered domestic partnerships. While some states recognize domestic partnerships, for federal tax purposes, the IRS does not consider registered domestic partners to be married.
Therefore, Kiri and Divina cannot file as Married Filing Jointly or Married Filing Separately because the federal government does not recognize their partnership as a marriage. Additionally, they cannot file as Qualifying Surviving Spouse because this status is reserved for a widowed person who still has dependents. Since neither Kiri nor Divina has dependents, the Single filing status is the correct and most favorable option for both of them for their 2022 federal tax return.