Answer:
D. Gave proof through the night that our flag was still there
Step-by-step explanation:
I believe it is D or B but i feel strongly for D as they flag was still their if the soldiers didn't fight a a fight the flag wouldn't be their it would be another flag there of no at all also they stated "Gave proof" they proved their self as being good soldiers.
and perilous does mean full of danger or risk so yeah