In the following statements, which one is an opinion? ( )

A、Tuberculosis (肺结核) is a global epidemic. About 9 million new cases are diagnosed worldwide every year, one-quarter of them in Africa.
B、Since it was first established in 1901, the Nobel Prize in physiology or medicine has been awarded 109 times to 216 scientists.
C、Students would welcome a change in the school uniform policy.
D、Harry Potter studies at Hogwarts School of Witchcraft and Wizardry.