Which of the Following Categorical Syllogisms Is in Standard Form

Which of the following categorical syllogisms is in standard form?

A) All dogs are mammals. Cats are not dogs.
So, no cats are mammals.
B) All dogs are mammals. No fish are mammals.
So, no dogs are fish.
C) Some mammals are small. No whales are small.
So, no whales are mammals.
D) No whales are mammals. Some whales are fish.
So, some fish are not mammals.