Which of the Following Individuals Would Be Permitted to Authenticate

Which of the following individuals would be permitted to authenticate defendant Tom Smith's handwriting at trial?

A) Mary Smith, Tom's mother, who regularly received letters from Tom while he was in custody awaiting his trial
B) Jerry, Tom's cellmate, who often read Tom's handwritten letters to his attorney
C) Harry, Tom's co-defendant, who watched Tom write the document in question
D) All of the above
E) None of the above