Explanation:

- Option 1: Crash land an aeroplane

This suggests a literal event where a plane crashes, but it doesn't capture the metaphorical sense of "going down in flames."

- Option 2: Get hit by a burning cracker

This is a literal event and doesn't fit the idiomatic use, which broadly pertains to failure, not fire-related accidents.

- Option 3: Fail completely

The phrase "go down in flames" is often used to describe a situation where someone or something fails spectacularly and publicly.

Correct Answer

- Option 4: Get completely burnt

This leans towards a literal interpretation, which is not what the idiom means in context.