So B is definitely not correct. A is not super important. Gotta wither be C or D but it is probably C because that is why they did revisions to the AoC because they needed a new system.
Answer: C
In world war one most airplanes were used as fighter airplanes. With machine guns in them to be used against the enemy
Yes it is actually because they both do the same stuff
you worded it weird but the (Cuban Missile Crisis) was what some would call the last stand between the US and Russia lunching a nuclear attack.