听力原文： Eaton-wielding police in Belgrade clashed with hundreds of student demonstrators

trying to march to parliament to support demands for early elections. The student leaders say 50 people were injured as police intervened to keep the marchers away from the parliament. State-run television accused the students of provoking the officers. Opposition parties later staged a separate march, but police used cordons to block those demonstrators from marching to the assembly.

Student demonstrators demanded ______.

A．the president's resignation

B．early elections

C．free elections

D．severe punishment for corrupted officials