Only conclusion I follows
Only conclusion II follows
Either I or II follows
Neither I nor II follows E. Both I and II follow
Answer is Right!
Answer is Wrong!
The correct answer is $\boxed{\text{E}}$.
The first statement is “All windows are doors.” This means that every window is a door. The second statement is “No door is wall.” This means that no door is a wall.
The first conclusion is “No window is wall.” This follows from the first statement, because if every window is a door, then no window can be a wall. The second conclusion is “No wall is door.” This follows from the second statement, because if no door is a wall, then no wall can be a door.
Therefore, both conclusions I and II follow.