Married couple John and Mary Mason have separated. Mary supported their two children after the separation and paid 100% of the cost of maintaining the home in which the children lived after John moved out in September, 2021. The parties remain married as of December 31, 2021. John refuses to file a joint return for 2021. Which statement is true regarding Mary's filing status on 2021 Form 1040?

A Mary may claim abandoned spouse filing status B Mary may file as a head of household

C Mary must file as married separate

D Mary may still file a joint return, thereby forcing John to also file jointly

E None of the above