Identify a true statement about the crime of perjury.
a. At common law, perjury had to be proven by the testimony of a single witness.
b. Materiality is a major aspect of perjury, and most jurisdictions require that a matter in which an oath is required by law be material.
c. Proof of the element of intent in a perjury case requires proof that the witness believes that his or her given testimony is true.
d. Modern statutes have narrowed the offense of perjury to exclude false swearing, which is a misdemeanor.