Answer:
I would say your best answer choice would be A - Starvation
C and D don't make sense towards the context of the question, and dont fit.
With B, how would their new rifles kill them, saying there were any new rifles at the time
A, Think about it. You're sitting in carved out ditches, with hundreds or thousands of people across a long range on land. Of course food is going to run out or get on really short supply as getting more supplies would be difficult for the situation they were in.
Step-by-step explanation:
- Eijiro <3