Most of europe is 300 miles from the seacoast. why is this a good thing?

I'm thinking the answer is A on this one

A closeness to the coast is usually seen as a good thing: it's combined with good trade possibilities, which are beneficial to a country. 

I think that the best answer is a) A landlocked area hampers trade with other countries and therefore stifles the economy.

it does mean more farming land, but this might not be more attractive than trade routes. 

A, c, and d are the answers

Yes all of them are right