单项选择题

Which of the following best explains the sentence "That's not a black problem or a white problem: it's a British problem." in the last paragraph

A. Black boy's underachievement is not a problem of the black only but of all the British.
B. Differentiating between black people and white people is a racial discrimination against the black.
C. The origin of black boys' underperformance lies in the British education system, rather than any ethnical difference.
D. Black boy's underperformance is not a racial problem but an educational problem of all British.