Aubrey Devlin works as a loan officer for Dawn Bank. Aubrey is concerned that a customer may claim at a later stage that he/she was not the person who signed collateral documentation. Below is a list of possible remedies that Aubrey may pursue to ensure that a customer will not be able to claim that a signature did not belong to him or her. Select the best option on the list. a. Aubrey should ask for the customer's fingerprints to be taken. b. Aubrey should only rely on collateral already held by Dawn Bank. c. Aubrey should refuse any transaction where collateral is required. d. Aubrey should ensure that the documentation is signed in front of two witnesses and that the two witnesses also sign the documents as witnesses