(A) the ship has docked
(B) ** the end of the war
(C) they are back from a trip
(D) their trip was frightening
EXPLANATIONS BELOW
Concept note-1: -Answer. HOPE THIS HELPS YOU! The fearful trip refers to the American Civil War, the slaves were fighting for their freedom. The fearful trip is done, this line means that, after all the struggle, finally, they earn victory and they rejoice as they arrive on the deck.
Concept note-2: -In the poem Whitman likened the presidency of Lincoln to a captain steering a ship. The fearful trip was the American Civil War that was ending, but whose end was not formalized. Lincoln was assassinated in April and the surrender of the Confederacy was less than one month later in May 1865.
Concept note-3: -“O Captain! my Captain! rise up and hear the bells; Rise up-for you the flag is flung-for you the bugle trills…”
Concept note-4: -My Captain!, three-stanza poem by Walt Whitman, first published in Sequel to Drum-Taps in 1865. From 1867 the poem was included in the 1867 and subsequent editions of Leaves of Grass. “O Captain! My Captain!” is an elegy on the death of Pres.
Concept note-5: -In the first stanza, Whitman calls upon the Captain (Lincoln) of the Ship (USA) that ‘fearful trip’ (dreadful Civil War) has come to an end. The people have won the victory at last, which they quested for i.e. the victory of the union.