Canada is surrounded by all the following bodies of water except
a. baffin bay
b. the labrador sea
c. the arctic ocean
d. the gulf of mexico

The Gulf of Mexico is very far from Canada! In fact it is separated from Canada by the entire US, as it's only on the southern side of Florida, Alabama and other states- it also borders Mexico, which Canada does not border directly.

So the correct answer is the Gulf of Mexico.

The answer is the magnetosphere.