Cortez can likely qualify to file as head of household if he is unmarried, provided more than half of his son Mario's support as a full-time student, and if Mario lived with him for more than half the year.
The question pertains to the ability of Cortez to file as head of household on his taxes. To qualify for this status, a taxpayer must be unmarried or considered unmarried at the end of the year, pay more than half of the home's upkeep for the year, and have a qualifying person live with them for more than half the year. In this situation, since Cortez's son Mario is 20 and a full-time student, Mario can be considered a qualifying child if he lived with Cortez for more than half the year, Cortez provided more than half of his financial support, and considering Cortez is single. Therefore, it is likely that Cortez can file as a head of household if these conditions are met.