In which of the following statements is the idiom used incorrectly?
(A) An ordinary, overweight woman sings well and is admired by the world. Every dog has its day!
(B) My grandma still uses her typewriter even though we have given her a computer. You can never teach an old dog new tricks.
(C) The professor is mean at heart. His bark is worse than his bite.
(D) It is a dog-eat-dog world. You had better be careful not to fall for others’ trick.