Explain how the Battle of Britain was a turning point in World War?

This stopped the steady invasion of The Lightning war or "Blitzkrieg"

Explanation:

The battle over Britain was a time of silent dread, waiting for the Germans to come onto the British soil was a terrifying image to overcome. The Blitzkrieg has toppled over the other countries with supposed large and proud militaries in a matter of weeks. Britain was in several words literally the last man standing. By some Miracle, the British pilots were more skilled, and held their ground until Operation Barbarossa, which led to Germany diverting resources to Russia.

your answer would be (a)