Answer:
b. Veteran trainers offer a great deal of love and discipline to whatever dogs they train.
Step-by-step explanation:
The noun clause "whatever dogs they train" is the object of the preposition to.
a. These experts say that the best time to begin a dog’s training is when the dog is still a puppy.
This is a noun clause that functions as a predicate nominative.
c. These experts say that the best time to begin a dog’s training is when the dog is still a puppy.
This is a noun clause that functions as a direct object.
d. Whoever trains a dog should have experience.
This is a noun clause that functions as a subject.