Which of the following sentences contains a dangling modifier?
a. walking through the woods, we could see there were animals everywhere.
b. opening the door, we could see that the room was very large.
c. looking through the window, the room seemed very large.
d. none of these

The sentence that contains a dangling modifier is C) Looking through the window, the room seemed very large. 
It is dangling because we don't know who the participial phrase looking through the window refers to. It certainly doesn't refer to the room, the room wasn't looking through the window.

According to a gossip website they are around 40 .. i hope it's not a question from your book!