A set of animals includes a dog, a cat, a rabbit, and a parrot. The dog is a mammal, the cat is a mammal, the rabbit is a mammal, and the parrot is a bird. Which of the following is the odd one out?
In a coded relation, if M + N means M is the aunt of N, M - N means M is the uncle of N, and M × N means M is the cousin of N, what is the relationship of O if M + O - N?