Which of the Following Applies to Signers When Determining Signature

Which of the following applies to signers when determining signature liability?

A) The location of the signature on an instrument usually determines the signer's capacity.
B) Qualified indorsers and agents are primarily or secondarily liable on the instrument.
C) Most indorsements appear on the front side of the instrument.
D) It is usually presumed that the indorsement is someone else's signature unless the instrument clearly indicates that it is that of the indorser.