Respuesta :
Well, none of these options really explain what this line actually means. Whitman wanted to say here that he will die, just like everybody else, and that it is okay, it is part of life cycle. So, I'm guessing the closest answer could be A) That his body has dissolved into dirt.
The correct answer is A. That his body has dissolved into dirt.
Whitman is writing about the transience of life, and how everyone will have to die at one point. When he says that he is just the dirt under somebody's soles, he means that he will turn to soil once he is dead, and that he will be one with nature, just like everyone else. B and C are silly choices, and D is wrong because he is also praising himself in the poem rather than undermining his own worth.