Questions 14 to 17 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions. Now listen to the passage. The Vaccination Week campaign was launched ______.

A．a less important role
B．an equally important role
C．an insignificant role
D．the least significant role

A．The dances of a Native American dance troupe.
B．How Native American ceremonial dances are classified.
C．Variations of a basic dance among Native American tribes.
D．How Native American artists are trained.