Three statements are given, followed by three conclusions numbered I, II and III. Assuming the statements to be true, even if they seem to be at variance with commonly known facts, decide which of the conclusions logically follow(s) from the statements.

Statements:

All trees are walls.

No wall is a door.

Some doors are rooms.

Conclusions:

I. Some rooms are walls.

II. No trees are doors.

III. All walls are trees.