A defendant was charged with second-degree murder for allegedly stabbing the victim to death during a bar fight. At trial, the prosecution called an eyewitness who testified that the defendant, who was right-handed, stabbed the victim with a broken beer bottle using his right hand. The defense then called a forensics expert whose training and expertise was in knife and gunshot wounds. After considering and applying reliable principles and methods to the facts, the expert testified that the entrance wounds appeared to be consistent with someone who was left-handed. In addition, the wounds did not appear to come from a broken beer bottle, but rather a sharp tool, such as a knife or a pair of scissors. Is the expert's testimony proper? A. Yes, because the subject matter of the expert's testimony is reliable and relevant, and his opinion is proper.
B. Yes, because the prosecution opened the door by calling the eyewitness to testify about how the victim was stabbed.
C. No, because the opinion of an expert who does not have personal knowledge cannot be used to refute the opinion of a lay person with personal knowledge.
D. No, because the expert was not able to identify the type of murder weapon with an adequate level of scientific certainty.