3. identify the sentence in which the underlined clause is a noun clause that functions as the object of a preposition.

a. these experts say that the best time to begin a dog’s training is (when the dog is still a puppy.)
b.(whoever trains a dog) should have experience.
c. veteran trainers offer a great deal of love and discipline to (whatever dogs they train.)
d. these experts say (that the best time to begin a dog’s training) is when the dog is still a puppy.