请阅读短文，完成第21-25小题。 Photographer Teresa Berg replaces a Rottweiler’s collar with a pink scarf. She picks a string of pearls to complement a dachshund’s coat. She is taking glamour shots of shelter dogs, hoping her spiffed-up subjects will be adopted more quickly."Most photos show dogs in cages, looking dirty, and mangy," says Berg. "I consider my work like an antismoking campaign. We have to make adopting cool."Her father wouldn’t allow her a dog of her own as a kid. He did, however, show her how to use a camera. Together, they took pictures and developed them at his office.Living in Dallas at 24, Berg found her perfect roommate on the street: a Border collie-Shetland sheepdog mix she named Gpsy. Berg always has a soft spot for the ones that don’t have anyone to love.For years, she worked as a real estate agent, but she quit in 2006 to launch a photography business. Searching the Internet for a dog to adopt as a companion for Max, her Pomeranian, she was instantly put off by the photos online:"They had dirty laundry, dirty dishes, and empty pizza boxes in the background," she says.Berg finally found Flash, a 12-year old long-haired dachshund who was a Dallas rescue dog. She went to pick him up and ended up volunteering to take pictures of all the rescued dogs there for free. As more dogs went to the program, she took their pictures too. In the following year, after the photos went up on the website of the Dallas-Fort Worth Dachshund Rescue, the group’s director noticed that adoptions had doubled compared with last year. She attributed this to the professional photos. "When dogs are adopted that quickly, it makes room for others off the streets, "Berg says.Over the years, Berg has developed some tricks to snap flattering pictures: position dogs so that light falls on their faces, and shoot at eye level. In 2011, hoping to inspire more photographers, Berg posted video seminars on focusonrescue.com. About 75 people per month now watch her offer tips for taking quality pet photos. She’s gratified to see the recent wave of well-shot dog photography on shelter websites and social-media sites.In the past couple of years, Berg has added two dogs to the Dallas home she shares with Flash and her husband: a dachshund named Jasper and a Pomeranian named Maggie:"I want to take all the shelter dogs home; that’s the hard part," Berg says."I have a particular affinity for dogs with gray muzzles." What does the underlined word "muzzles" in the last PARAGRAPH most probably mean

A. Mouth and tongue.
B. Nose and mouth.
Chest and shoulders.
D. Elbow and forearms.