Which taxpayer may file as head of household? $($If the scenario states the dependent is a qualifying child or qualifying relative, it means they have passed all the dependency requirements.$)$

Adam is single. Adam and Lee are cousins. They lived together in Adam's home all year. Adam paid all of the cost of maintaining the home for the year. Lee is a qualifying relative dependent of Adam.

Cortez is single. His son Mario $($age $20)$ lived with him all year. Mario is a full$-$time student, and did not provide more than half of his own support. Mario is a qualifying child dependent of Cortez. Cortez paid all the cost of maintaining the home for the year.

Ebony is single. Her friend, Dalia, is her qualifying relative dependent. Ebony and Dalia lived together all year. Ebony paid all of the cost of maintaining the home for the year.

Rico is single. His girlfriend Marie lived with him all year. Marie's daughter $($from a previous marriage$),$ Sofia $($age $8),$ also lived in the home all year. Rico paid all of the cost of maintaining the home for the year.