Bob Is on Trial for the Murder of Carl

Bob is on trial for the murder of Carl. The prosecution is basing its case on the theory that Bob forged Carl's will, which revoked Carl's original will and made Bob the sole beneficiary, before killing Carl. Carl's original will was witnessed by Donna and Eve. The prosecution wants to introduce several checks drawn on Carl's personal checking account that bear Carl's signature to show that the signature on the allegedly forged  will was not made by Carl. How can these signatures be authenticated?

A) The checks can be used for this purpose only if someone testifies that they saw Carl sign them.
B) The checks can be used for this purpose only if a forensics document examiner testifies that they are authentic.
C) The jury can compare the checks to the will and decide if they were made by the same person.
D) The checks can be used only if the bank employee who witnessed Carl sign the signature card for the checking account testifies.