The answer is D: Hamm.
In this play by Samuel Beckett, one of his most renowned and remarkable plays, the Irishman presents us with four characters, Hamm, who is unable to stand; Clov, his servant, unable to sit down; and Nagg and Nell, Hamm´s parents. The story develops a relationship of animosity between Hamm and Clov —Hamm always giving orders and commands to his servant— a relationship that, notwithstanding, they can´t seem to break or stop. The play often suggests that beyond the room where the play takes play, there is no outside (though sometimes Clov is instructed to look outside and watch for any changes or remarkable events: which never come).
