单项选择题

Jessica Bucknam shouts "tiao! "(tee—ow) and her fourth-grade students jump.
"Dun!"(doo—wen) she commands, and they crouch(蹲). They giggle(吃吃地笑) as the commands keep coming in Mandarin Chinese.
Half of the 340 students at the K-5 school are enrolled in the program. They can contine studying Chinese in middle and high schools. The goal.. to speak like natives.
About 24,000 American students are currently learning Chinese. Most are in high schools. But the number of younger students is growing in response to China’s emergence as a global superpower.
"China has become a strong partner of the United States," says Mary Patterson, Woodstock’s principal. "Children who learn Chinese at a young age will have more opportunities for jobs in the future."
Isabel Weiss, 9, isn’t thinking about the future. She thinks learning Chinese is fun. "when you hear peo- ple speaking in Chinese, you know what they’re saying,’ she says. "And they don’t know that you know. ’
In response to the fact that ______,more American Students are learning Chinese.

A.the United States is the only superpower in the world
B.international trading is becoming globalized
C.partnership is encouraging business and trade
D.China is emerging as a new superpower in the world