Statement: "Do not lean out of the moving train", - A warning in the railway compartment.

Assumptions:
I. Such warning will be some effect.
II. Leaning out of the moving train is dangerous.
III. It is duty of railway authorities to take care of passengers safety

I, II, III implicit

The correct answer is Option (4) → I, II, III implicit

The warning against leaning out of moving train is made to heed against the dangers involved.

So, both I and II are implicit.

Since the warning has been put up in the railway compartment,

so III is also implicit.