Concept:
The adjective historic is used to describe an event that is important in history and has great significance. The Quit India Movement was one of the most important events in India's struggle for independence.
Step 1: Understand the context.
The Quit India Movement, launched in 1942 under the leadership of Mahatma Gandhi, played a major role in India's freedom movement.
Step 2: Examine the options.
• Hysterical -- excessively emotional.
• Historic -- important and memorable in history.
• Hypothetical -- based on assumption.
• History -- a noun, not suitable as an adjective here.
Step 3: Select the correct word.
Since the movement had immense historical importance, the correct choice is historic.
\[
\boxed{\text{Historic}}
\]