Question

Hitler intended to defeat Great Britain by

Answer 1

Answer;
Hitler intended to defeat Great Britain by; A massive bombing attack;

Explanation; 
After the French armistice was signed on 22 June, Britain was the only country resisting Germany. Hitler did not wish to invade Britain, after the fall of France, he assumed the British would simply surrender. 
Hitler was therefore surprised when Britain did not surrender. On july 16 he gave a directive which authorized detailed preparations for an invasion landing in Britain, code named operation Sealion.

Answer 2

Hitler intended to defeat Great Britain by "A- a massive bombing attack" since a crossing of the English channel would have required far more effort. He failed in this endeavor however.