In Wilfred Owen's World War I poem, "Anthem for Doomed Youth," all of the elements of a funeral are represented by the trappings of war. The guns act like the tolling of bells for the dead; the "stuttering rifles' rapid rattle" serve as hastily-said prayers.

Another aspect of the funeral process is the placement of candles...

...church candles, or the candles lit in the room where a body lies in a coffin...

Mourners would often light candles at the side of a coffin while a body was lying in state; people would come to a funeral parlor or someone's home, to view the body and pass one's last respects. Owen refers to literal candles that will be absent on the battlefield. In these circumstances, Owen wonders where the candles will come from now. They will not be held in the hands of [alter] boys, but in the eyes of the "boys" who have died:

What candles may be held to speed them all?
Not in the hands of boys but in their eyes
Shall shine the holy glimmers of goodbyes.

I believe the clue to the correct response to this question is found in "heaven." The only thing that will be like a candle will be the "holy glimmers of goodbyes" in the eyes of those who are dying. The "glimmers of goodbyes" indicate the dying of the body and the passing of the spirit into a different realm, which would be "heaven." The goodbyes are said at the moment of death, preparing the young soldier not to return "home," as he is dead; only his body may return home. "Dinner" is not a correct answer as the young, doomed men have no hope of having dinner ever again. And there is no "church" in the middle of the mayhem of battle—and even if there were, what good will a church serve for a dead man?

The only plausible answer seems to be "heaven" because as the glimmer in the boys' eyes die, they will be sped to heaven; there is no other item in the list of answers where a young man would go that would be appropriate in the face of the passing of these "doomed youth." My answer would be "heaven."