(Please help me!!! my guess is either A or D but i want to make sure.)
Is the following definition of dog reversible? If yes, write it as a true biconditional.
A dog is a mammal.
a. The reverse is false.
b. The reverse is true. An animal is a dog if (and only if) it is a mammal.
c. The reverse is true. An animal is a mammal if (and only if) it is a dog.
d. The reverse is true. If an animal is a dog, then it is a mammal.