(! 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.