Which of these is NOT a requirement for being considered unmarried for tax purposes?

The person must file a separate return from their spouse.

The person's spouse must not have lived in the home at any time during the last six months of the tax year.

The person and their spouse must have provided more than half the cost of maintaining their home for the tax year.

The home must have been the principal place of abode of the taxpayer and their dependent son, daughter, or eligible foster child (qualifying child or qualifying relative) for more than half the tax year.