Plaintiff sued Defendant for breach of a commercial contract in which Defendant had agreed to sell Plaintiff all of Plaintiff's requirements for widgets. Plaintiff called Expert Witness to testify as to damages. Defendant seeks to show that Expert Witness had provided false testimony as a witness in his own divorce proceedings. This evidence should be
admitted only if elicited from Expert Witness on cross-examination. admitted only if the false testimony is established by clear and convincing extrinsic evidence. excluded, because it is impeachment on a collateral issue.  excluded, because it is improper character evidence. 
Question: Plaintiff sued Defendant for breach of a commercial contract in which Defendant had agreed to sell Plaintiff all of Plaintiff's requirements for widgets. Plaintiff called Expert Witness to testify as to damages. Defendant seeks to show that Expert Witness had provided false testimony as a witness in his own divorce proceedings. This evidence should be
A. admitted only if elicited from Expert Witness on cross-examination.
B. admitted only if the false testimony is established by clear and convincing extrinsic evidence.
C. excluded, because it is impeachment on a collateral issue. 
D. excluded, because it is improper character evidence. 
Answer: