Question

Which argument is valid?



A.


If an animal can swim, then it has fins.
If an animal is a fish, then it has fins.
If an animal can swim, then it is a fish.



B.


If a polygon is a square, it has four right angles.
If a polygon is a rectangle, then it has four right angles.
If a polygon is a rectangle, then it is a square.



C.


If it is a dog, then it barks.
If it has a tail, then it is an animal.
If it is a dog, then it barks and has a tail.



D.


If a number is divisible by 12, then it is divisible by 6.
If a number is divisible by 6, t