While testifying as a witness in a civil trial, Walters was asked on cross-examination if he had been convicted in the circuit court of Jasper County of stealing $200 from his employer on August 16, 1977. Walters said, "No, I have never been convicted of any crime." In fact, Walters had pleaded guilty to such a charge and had been placed on probation. Walters was then charged with perjury on the ground that his statement denying the conviction was false. A statute in the jurisdiction defines perjury as knowingly making a false statement while under oath. At trial, the state proved Walters' statement and the prior conviction. Walters testified that the attorney who represented him in the theft case had told him that, because he had been placed on probation, he had not been convicted of a crime. Walters had served his probationary period satisfactorily and been discharged from probation. The alleged advice of the attorney was incorrect. If the jury believes Walters, it should find him 
guilty, because his mistake was one of law.  guilty, because reliance on the advice of an attorney is not a defense.  not guilty if the jury also finds that his reliance on the attorney's advice was reasonable. not guilty, because he lacked the necessary mental state