Overthinking becomes your enemy when this riddle boggles your mind

A riddle is often just a trick by the way it is phrased but after it manages to lure certain readers in, the answer would be staring right at your face. 

Such a riddle is this one which left Olivia fighting with her friend over the right answer as she mentioned in her Facebook post. 

She managed to rope in others as well into the madness and now it is your turn.

Remember, do not over think or you will get even more confused.