Canada is in a strong position to trade with nations around the world because it
a. has a trade agreement with the united states
b. is a middle power
c. is a member of the british commonwealth
d. has ports on the atlantic and pacific coasts

The reason why Canada is in a strong position to trade with nations around the world is because it has ports on the Atlantic and Pacific coast - d.

This means they are able to effectively utilize this condition (where they are located) and gain a lot of benefit from it, compared to other nations around the world at least.