Multi-choice problem: Continue writing the next sentence in this paragraph:

How to diagnose canine anal sac problems
Locate your dog's anal sacs.
Look for two sacs on either side of your dog's anus, at the " twenty past eight " position on a clock face. The sacs should each be the size of a small grape and sit just underneath the skin.

(A). Look for one like this : Between the scrotum and anus. Two sacs should sit right over the scrotum, above the sacs.. (B). They should be about 0.05 centimetres (0.04 in) wide and 3 centimetres (0.91 in) long. If your dog's sacs are not visible, check your dog's diapers frequently during the day.. (C). Your dog's anal sacs drain out onto his feces through small ducts. When your dog needs to toilet, the squeezing action forces a few drops of the smelly secretion out of the sacs and onto each bowel movement.. (D). You'll find one obviously to the rear of the anus. The two sacs should rotate a lot before you see one curling upwards..
(C).