单项选择题

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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.

In terms of nanotechnology, Kim was the first ().

A.to use it in washing machines
B.to come up with the idea
C.to introduce it to Korea
D.to apply it to socks