B Zhang did not commit a crime, Wang did, Li did not commit a crime, Zhao did, and Sun did not commit a crime.
C. All five employees were involved in the crime.
D. None of the five employees committed a crime.
This problem is not our common contradiction solving method. Everyone involved in the crime is lying, and all innocent people are telling the truth. We don't know who is telling the truth, who is lying, who is involved in the crime and who is innocent. At this time, we have to look for the characteristics and breakthrough of this problem again. Look at these four sentences. Who said them with characteristics? That must be a photo. Others only said one sentence, but he said two. Can't this get our attention? As long as we pay attention to this sentence, the problem will become very simple. You will find that Zhang's two sentences are contradictory in themselves. If Wang is the perpetrator, then Wang will definitely not say that he did it himself. So we can know that Zhang lied and Zhang was the initiator, so Wang was not the initiator, then Wang told the truth, then Li was the initiator, then Li lied ... This kind of logical reasoning will make everyone feel very simple. In fact, in the examination room, as long as Zhang commits a crime and Wang does not commit a crime, you can choose A directly, and you don't even have to push it below.