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 soothe a dog's itchy ears [title] Know when to see a veterinarian. [step] If you've noticed your dog constantly scratching his ears, get him examined. The vet will use a tool (otoscope) to examine deep inside the ear canal and check if the eardrum (tympanum) is intact. <sep> (A) If it is not, then make an appointment with your vet. [substeps] Before taking your dog out for walks around the neighborhood, do some research. (B) If it is, then the vet may suggest saline to help soothe his ear canal, since you'll also need an otoscope and binoculars. [substeps] Another possible cause of scratching your dog's ears is ear infection. (C) The vet may also use chemicals (papyrus, mineral oil, panacur, or dolomide) to treat the ear canal. [title] Use an otoscope to inspect your dog's eyes. (D) The vet will also look for other causes of itchy ears. For example, the vet may swab your dog's ears to diagnose an infection.
A:
D