The correct answer is D. No improvement.
The phrase "passed off peacefully" means that the demonstration ended without any violence or disruption. The other options are incorrect because they have different meanings.
- "Passed out" means to lose consciousness.
- "Passed away" means to die.
- "Passed on" is a euphemism for "died."
In this context, the phrase "passed off peacefully" is the most accurate and appropriate way to describe the outcome of the demonstration.
