In Melendez-Diaz V

In Melendez-Diaz v. Massachusetts, Melendez-Diaz was charged with distributing cocaine and with trafficking in cocaine. At trial, the government presented evidence that the bags seized in the case contained cocaine, through an expert witness, who had not conducted any of the laboratory analysis, who testified that according to three "Certificates of Analysis" that the bags taken from the defendant and his associates contained cocaine. Under the facts of this case:

A) the expert witness testimony was lawfully permitted concerning the contents of the bags of cocaine because another expert had conducted the laboratory analysis and the three "Certificates of Analysis" proved the nature of the contents.
B) the expert witness testimony was lawfully allowed into evidence because this has been the custom for many years.
C) the expert witness should not have been allowed to testify concerning the contents of the bags because such testimony would clearly have been hearsay evidence, and no exception exists to allow such evidence.
D) the expert witness should not have been permitted to testify concerning the contents of the bags because he had no first-hand knowledge, and such testimony violated the defendant's due process rights under the Sixth and Fourteenth Amendments to confront his accusers.