Suppose it is true that "a falling tree makes no sound if no people were there to hear it$,"$ then which of the following statement must be true $($in the sense that it is logically entailed$)?$

All trees make some sound when they fall.

A falling tree will make a sound even if no people were there to hear it$.$

If some people were there to hear it$,$ then the falling tree would make a sound.

If a falling tree makes no sound, then no people are there.

If the tree makes a sound, then some people must be there to hear it$.$