People who are worried about bad breath often reach for a toothbrush or a gun. But in the future, personal breath monitoring may include far more than fresh breath. In face, breath is so rich in chemical compounds that fully understanding it has proved challenging. Each breath contains gases like carbon dioxide, the volatile remains of recent snacks, medicines and even compounds taken in from things like carpeting or various kinds of air pollution. But breath detectors can sort out these substances with increasing sensitivity . Scientists are building electronic sniffers that examine the exhaled air for signs of cancer, asthma , and other diseases. "There are clear signatures in the breath for liver disease, kidney disease and heart disease. Breath is a rich mixture that can reflect out state of health and disease." said Dr. Raed Dweik, director of the Cleveland Clinic, adding "Breath analysis is the future of medical testing." He and his partners are testing a desktop system called BreathLink for use in rapid identification of diseases. The system is designed to work wherever there is an Internet connection. To use BreathLink, a person breathes into a long tube, and a breath sample is collected and analyzed within the system. Then it can detail chemical concentrations of the breath in graphics. Dr. Raed Dweik said, "If you examine patients of asthma, you will find they have higher levels of nitric oxide in their exhaled air. It reflects their abnormal symptoms in the lungs." His tests have reached 85 percent accuracy so far in spotting people with some illness. But some trained dogs, he pointed out, can sniff out cancer with 99 percent accuracy--although without the ability to identify particular compounds the way some detectors can. "We are getting better and better," he said. "But whether we will ever approach the accuracy of the dog--we don't know." What's the author's attitude towards the future of breath detectors? A) Indifferent B) Positive C) Doubtful. D) Critical.
A:
B