A

"In only six clays I lost seven pounds of weight. "
"Two full inches in the first three days!"
These are the kinds of statements used in magazine, newspaper, radio and television ads. , promising new shapes and new looks to those who buy the medicine or the device. The promoters of products say they can shape the legs, slim the face, smooth wrinkles, or in some other ways to add to beauty or desirability.
Often such products are nothing more than money-making things for their promoters. The results they produce are questionable, and some are dangerous to health.
To understand how these products can be legally promoted to the public, it is necessary to understand something of the laws covering their regulation. If the product is a drug, FDA (Food and Drug Administration)can require proof (证明) under the Food, Drug, and Cosmetic Act that is safe and effective before it is put on the market. But if the product is a device, FDA has no authority to require pre-marketing proof of safety or effectiveness. If a product already on the marker is a danger to health, FDA can request the producer or distributor to remove it from the market voluntarily, or it can take legal action, including seizure (查封) of the product.
One notable case a few years ago involved an electrical device called the Relaxacisor, which had been sold for reducing the waistline. The Relaxacisor produced electrical shocks to the body through contact pads. FDA took legal action against the distributor to stop the sale of the device on the grounds that it was dangerous to health and life.
Obviously, most of the devices on the market have never been the subject of court proceedings (法律诉讼), and new devices appear continually. Before buying, it is up to the consumer to judge the safety or effectiveness of such items.

FDA can ask for the proof of safety and effectiveness of a product ______.

A．if it is a drug

B．if it is a device

C．if its consumers make complaints

D．if its distributors challenge FDA’s authority