B. Read the passage carefully, then choose the correct answer.

The July 13, 2000, signing of the Bilateral Trade Agreement (BTA) between the U.S. and Vietnam was a significant milestone for Vietnam‘s economy. The BTA provided for Normal Trade Relations (NTR) status of Vietnamese goods in the U.S. market. Access to the U.S. market will allow Vietnam to hasten its transformation into a manufacturing-based, export-oriented economy. It would also concomitantly attract foreign investment to Vietnam, not only from the U.S., but also from Europe, Asia, and other regions.

On January 11, 2007, Vietnam became WTO‘s 150th member, after 11 years of preparation, including 8 years of negotiation. Vietnam‘s access to WTO should provide an important boost to Vietnam‘s economy and should help to ensure the continuation of liberalizing reforms and create options for trade expansion. However, WTO accession also brings serious challenges, requiring Vietnam‘s economic sectors to open the door to increased foreign competition.

Although Vietnam‘s economy, which continues to expand at an annual rate in excess of 7 percent, is one of the fastest growing in the world, the economy is growing from an extremely low base, reflecting the crippling effect of the Second Indochina War (1954-75) and repressive economic measures introduced in its aftermath. Whether rapid economic growth is sustainable is open to debate. The government may not be able to follow through with plans to scale back trade restrictions and reform state-owned enterprises.

Reducing trade restrictions and improving transparency are keys to gaining full membership in the World Trade Organization (WTO), as hoped by mid-2006. The government plans to reform the state-owned sector by partially privatizing thousands of state-owned enterprises, including all five state-owned commercial banks.

She notified security by telephone________ she heard something suspicious going on in the elevator.