Which of the Following Arguments Most Clearly Commits the Fallacy

Which of the following arguments most clearly commits the fallacy of false alternative?

A) The light switch isn't turned on, so it must be off.
B) Diane is not rich, so she must be poor.
C) There is life on Earth, so the Earth must not be lifeless.
D) This toad has a definite sex, and it is not male, so it must be female.
E) Either some form of oxygen is present in the room or no human can survive there.But humans can survive there, so there must be some form of oxygen in the room.