C. an attempt to economically isolate Great Britain.
Explanation:
Napoleon's Continental System was "an attempt to economically isolate Great Britain."
This is evident in the fact that Napoleon's Continental System made the decrees of Berlin and Milan in 1806 and 1807 respectively which declared blockade to specifically incapacitate Great Britain economy through the wreckage of British commercial activities.
This is to ensure that French allies and other neutral not go into trading activities with Great Britain.
