Read the following passage and questions, then choose the right answer from options, the answer should be one of A, B, C, D.

<passage>:
The transformation of American dentistry from drill-and-fill to shoot-and-loot is an unlikely business success story of the '90s, a case study in how a profession can work itself out of a job and still prosper. Dentists, after all, are supposed to be extinct by now. While they happily (and profitably) scraped teeth and filled cavities during the '60s and '70s, fluoride was quietly choking off their revenue stream. The percentage of children with cavities fell by half and kept falling. People stopped going to the dentist, because they didn't need to. At the same time, the government funded dental-school construction, spilling new dentists into a saturated market. Many found themselves cleaning teeth for $10 an hour in mall clinics. In 1984, Forbes magazine forecast the end of the profession. Only a few lonely dentists would survive to fill the few remaining cavities, the last vestiges of a once-great civilization on Long Island. Some dentists dress up these cosmetic measures in medical scare talk. A friend of mine just quit a dentist who was pressuring him to whiten his teeth as a "preventive measure." (To prevent what? Yellow teeth?) Many dentists claim, without scientific evidence, that the mercury in amalgam fillings is dangerous. They urge patients to replace the excellent amalgam with plastic fillings at four times the price. Dentists make a killing on bad breath--or "halitosis," as they prefer to call it. Breath clinics have sprouted up all over the country and are heavily advertised on the Web. They terrify patients with a "halimeter," a new gadget that measures a nasty smelling chemical called methyl mercaptan. Armed with the halimeter proof, the dentist then dangles expensive mouthwashes and tongue scrapers in front of the patient. Never mind that you can get the same results for free with careful brushing and basic tongue-scraping. The machine makes the sale. "Now that there is this machine that can document your complaint and can put a number on it, it motivates a patient to actually do something about it. But the treatments available now are the same ones that have been available for 15 years," says Hartel. Entrepreneurial dentists market this elective care with trained aggression. Dental management organizations often require their employees to recite a quasisales script guiding patients toward profitable cosmetics. Ads in the Journal of the American Dental Association and on the Web promote tapes and classes on marketing techniques. One person I know quit his dentist when he spied a pamphlet in the office instructing the dentist in how to get his patients to "trade up" to more expensive treatment. The ADA's annual conference is overflowing with seminars on topics such as "how to move your patients to 'yes.' " The industry calls this technique "treatment acceptance," a marvelous euphemism for parting you from your money. According to the ADA's journal, this year's ADA conference will include an all-day "Treatment Acceptance" seminar "for the dental team that is fed up with patients accepting only what insurance covers or asking for alternative cheaper treatment plans. Involve the entire team in creating the strategies for patients to accept optimum care." This hard sell is critical in dentistry in a way that it isn't in other medicine because of the profession's brutal economics. Dental insurance covers only 44 percent of Americans (compared to more than 80 percent for health insurance), and provides skimpy coverage for those who do have it. As a result, patients pay most dental costs--about 60 percent of them--out of their own pockets. Dental care is just another way to spend discretionary income, competing with a vacation or a new car. Dentists have to make patients want adult orthodontics in a way physicians don't have to make patients want a quadruple bypass. It's tempting to dismiss the whole industry as a scam, particularly when dentists keep coming up with new ailments such as bruxism (teeth grinding), periodontal disease, malocclusion (bad bite), and microcracks. But these ailments are real, and our awareness of them shows how far dentistry has come. A generation ago, dentists filled teeth and cast dentures because that's all they knew. Decay killed so many teeth that fancier problems seldom arose. Since then, researchers have studied bonding, implants, and periodontal disease. Dentists can now make crowns that last forever, bridges that stay anchored, dentures that behave almost like real teeth. A generation ago, implants were a joke. Today's implants, affixed to your jawbone by a titanium screw, can hold for the rest of your life. Scientists have learned how bacteria can build up in gaps in the gum, cause infection, weaken the jawbone, and eventually murder teeth. New research links these periodontal bacteria to heart disease, diabetes, low birth-weight babies, and other nastiness you'd expect from bacteria running wild in the bloodstream. This is why your dentist hectors you to rubber-tip your gums, brush with a superconcentrated fluoride toothpaste, and wear a night guard to control your bruxing (which loosens teeth, opening pockets between teeth and gum, etc.). It's also why your dentist may bully you into gum surgery. It all seems unpleasant and slightly absurd--the night guard is "an excellent form of birth control," as one wearer puts it--but the alternative is losing your teeth at 40, getting dentures, and gumming your food. Dentistry is a hassle now because it works. Which brings us to the irony of dentistry's comeback: Just as patients love the dental care they should suspect, they resent the care they should appreciate. Aesthetic dentistry is the most profitable segment of the business because it is an easy sell. Put a camera in your mouth and you'll want whiter teeth, too. It is much harder to convince someone to poke her gums every night with a piece of rubber, to sleep with a choking plastic tooth guard, and to undergo four surgeries to fix a gum flap, all for a benefit that is decades away. The very success of dentistry has raised expectations so high that patients now object to any inconvenience. Americans under 60 believe keeping all their teeth is an entitlement: Telling them they need gum surgery to preserve their teeth makes them angry, not grateful--even though those teeth would have been goners 20 years ago. When I surveyed 100 friends and acquaintances about their dental complaints, few bitched about cosmetic dentistry that was foisted on them. They like their whiter, straighter teeth. No, they griped about the medically advisable treatments that their dentists prescribed, especially gum surgeries and mouth guards. Pity the poor dentist who abjures cosmetic dentistry but vigorously protects patients' teeth. Patients don't like periodontal treatment, so they suspect it's a rip-off. This could not be further from the truth. "Dentists are aware of providing what patients want," says Hartel. "I had a woman come in with a terrible toothache. She needed a root canal, but she did not want it. But she did want her teeth bleached, and she paid cash for it." Such is the triumph of American dentists: If they can't sell you what you need, they'll sell you what you want.

<question>:
How do dentists sell unnecessary cosmetic procedures to their patients?

<options>:
A All of the options are correct
B By relying on psychological tricks and societal pressure
C By using medical jargon to confuse the patient
D By implying that the procedures are more necessary than they really are

<answer>:

A