Why were most european trading posts set up on the west african coast?

a. europeans preferred nautical trade to trading across land routes.
b. europeans were ill-equipped to travel into the interior of africa.
c. africans had already set up coastal trading posts.
d. in fact, most european trading posts were actually in the saharan desert.

Its ACTUALLY Europeans preferred nautical trade to trading across land routes(since they werent used to African terrain)

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.

what is the question