The correct answer is E, as after his loss in the Battle of Trafalgar, Napoleon and his forces no longer attempted to invade Britain.
This battle thwarted the intention of the French to invade, or at least block, by sea to the United Kingdom and it supposed the beginning of the British naval power, that would last a century.
The Battle of Trafalgar gave the British absolute control of the seas not only during the Napoleonic campaigns, but also during almost the entire nineteenth century. Not in vain is Trafalgar dedicated to the most important square in the city of London.