In some people's opinion, this epidemic of the mad-cow disease has been at best a clumsy mistake of the British government, but some of the opponents scolded it as a ________.
句意：在一些人看来，这种疯牛病的流行充其量只是英国政府的一个笨拙的错误，但一些反对者则认为这是一场灾难。disaster灾难。disappointment失望。discredit失信。disgrace耻辱。因此，本题的正确答案为D。