(1) There are three ways to sign the bill: signature, seal or signature and seal. Among them: the way of signature is generally a way that individuals can adopt; Seal, which is a way that legal persons, other units and individuals can adopt; Signature and seal can enhance security, which is also the way adopted by legal persons, other units and individuals.
(2) The signatures of legal persons and other entities using bills shall have the following two kinds of signatures at the same time: in addition to the official seals of legal persons and entities, the signatures of their legal representatives or their authorized agents shall also be affixed. For units that open settlement accounts in banks, the reserved bank seal is the special financial seal, and the bill signature can also be the special financial seal plus the personal seal of the legal representative or authorized agent.
(3) The signature on the bill of exchange shall be the real name of the party concerned. This helps to prevent fraud.
So all the above answers are correct, and ABCD should be chosen.