Suppose you added an entry to the timeline in Question 16 to describe what the Aztecs were doing before the first entry on the timeline. Your entry might read:

c

explanation:

ww1 weapons: tank. tanks were used for the first time in the first world war at the battle of the somme. they were developed to cope with the conditions on the western front. the first tank was called 'little willie' and needed a crew of 3.

the anwser is a) to prevent military conflict