Detailed Instructions: In this task, you are given a context and four options. Each option is a suggested ending for the context. You should read the context and pick the best ending for the context. Please answer with "A", "B", "C", and "D".
Q: [header] How to help your dog whelp or deliver puppies [title] Take your dog to the veterinarian. [step] If your dog's pregnancy is planned, take her to the veterinarian for a check-up before breeding her. Bring her in again about 30 days into the pregnancy. <sep> (A) This gives the vet the opportunity to decide if the pregnancy is appropriate for breeding, and how many puppies the baby needs. The vet should also examine your dog's vulva-the pink uterus between the urethra and urinary tract. (B) The vet will run some simple tests to help detect pregnancy changes. These include a urine sample and x-rays, and then blood to measure uterine tissue. (C) If the pregnancy wasn't planned, take her to the vet as soon as you find out she's pregnant. [substeps] If you plan to breed your dog, it's recommended that you wait until she's at least 24 months old. (D) [substeps] Urinary tract infections often cause breeding. During this point, the vet will ensure your dog does not have urinary tract infections.
A:
C