Directions: Choose the most appropriate word to fill the blank (i).

Two soldiers of rival forces treat each other as an (i) ________ and are prepared to (ii) ________ each other down. However, had the two met each other in peacetime at say a restaurant or a bar, one might even have given the other a (iii) ________ or offered (iv) ________ help.

In the context of rival forces at war, soldiers view each other as 'enemy' - someone they're fighting against. Option B 'shoot' is incorrect because it's a verb, but blank (i) needs a noun to complete 'an _____'. Option C 'treat' is also a verb and doesn't fit grammatically. Option D 'monetary' means 'related to money' and makes no sense in this military context. 'Enemy' is the only noun that logically completes the phrase 'an (i) _____' in the context of rival forces.