In USVYoung,where Government Agents Put Federal Express Packages to Young Under

In U.S.v.Young,where government agents put Federal Express packages to Young under an x-ray to look at the contents,and he was convicted partly based on that evidence,the appeals court held that:

A) the conviction was overturned because there was no warrant to x-ray the packages
B) the conviction was overturned because Federal Express violated customer privacy rights
C) the conviction was upheld because the severity of the crime outweighed the usual requirement to obtain a warrant
D) the conviction was upheld because there was no need for a warrant
E) none of the other choices