In "Anthem for Doomed Youth," "the bugles" are likely to be playing a: -reveille -taps -retreat -attack -none of these

As with any of these kind of questions, it is very
important to read the word or phrase you are trying to define in the context of the poem
as a whole and especially the sentence in which it occurs. Contextual clues can help
reveal the meaning of such phrases, and so if you can detect those contextual clues this
will help you greatly in your understanding of such works of literature. Let us think
about the immediate context of this phrase then:

No mockeries now
for them; no prayers nor bells; Nor any voice of mourning save the choirs, –The shrill,
dementedchoirs of wailing shells; And bugles calling for them from sad
shires.

Thus the "bugles" come as part of the poem that mourns
angrily how the dead soldiers are only remembered by the "choirs" of "wailing shells"
and the "bugles calling for them from sad shires." The bugle is a musical instrument
that is normally played at military funerals, and thus the author is imagining the
funerals that these dead soldiers will have back in England. As "taps" means a bugle
call sounded at military funerals, this is the best answer to your
question.