To find Kim Hyung Gyoon’ s office in Samsung’s R&D complex, just follow the baskets of

dirt clothes. No, Kim is not running the company laundry. As chief of Samsung’s Washing & Cleaning Technology Group(WCTG), he’s the man behind a new washing machine that deposits tiny silver particles(small pieces of things) —about 1 / 10,000 the thickness of a human hair— onto clothes to make them germ-and-odor-free without the need of hot water. The device represents the first mass-produced application of this tape of nanotechnology — the science of very small structures—to home appliances. "In summer of 2002, I asked everyone in the office to take off their socks," says Kim. "took one sock from each person and placed it in a regular washing machine; the others were washed in a machine with the Ag+ Nano System. The next day, I asked everyone to check the odor of their socks after a day’s wear. One began produce a strong unpleasant smell, and the other was odorless."

Kim says he came up with the idea five years ago while on a business trip to Japan, where he learned of a brand of socks that retained their freshness even after many days of unwashed wear and tear. Tiny sticks of sliver with germ-killing chemicals were woven into the fabric. When he got back to Seoul, Kim applied the principle to washing machines.

According to the Korea Testing & Research Industry, Samsung’s device kills 99.9% of germs. Kim says garments stay germ-free for up to a month after being laundered. The Ag+ Nano device went on sale in March 2003 and costs around $1,150; the revolutionary technology is also being used in Samsung’s refrigerators and air conditioners.

No wonder: consumers seem to a little sliver in their spin cycles. Since Samsung’s nano-armed products were first launched, they have brought in an estimated $779 million in revenue. Overall, nanotech has been one of science’s fastest-growing fields in recent years, with potential applications in fields as diverse as energy production and toothpaste manufacture. The nanotech market is projected to be worth $1 trillion by 2015.

Which of the following best describes the nature of Kim Hyung Gyoon’s work？

A．Product development.

B．Market investigation.

C．Research designing.

D．Sales promotion.