It is A. <span>direct object</span>
In my opinion, the whole poem is quite ironic - although she is mentioning the exultation and the royal color of death, the poem itself begins with the narrator saying that she cannot breathe - that she doesn't want to die.
So, I would say that the ironic parts are:
Exultation is the going
Of an inland soul to sea, -
Past the houses, past the headlands,
<span>Into deep eternity!</span>
It led the US to war because there was a loss of American life in the incident.