Although the Olympic Charter, the official constitution of the Olympic Movement, proclaims that the Olympics are contests among individuals and not among nations, the International Olympic Committees assigns to the various National Olympic Committees the task of selecting national Olympic teams.以上长难句中that后面引导的从句类型是？

A. 宾语从句
B. 同位语从句
C. 定语从句
D. 主语从句