If the statement Some animals are not birds is given as false, then which of the following statements can be immediately inferred to be false?

The proposition No animals are birds must be false.

The given falsehood is the O proposition Some animals are not birds.

The contradictory of that O is the A proposition All animals are birds, which is therefore true.

If All animals are birds is true, its contrary No animals are birds cannot also be true.

Hence No animals are birds is inferred to be false.