A Bill of Exchange must be in writing and

1. Section 5 of the Negotiable Instruments Act 1881 requires a bill to be in writing and SIGNED BY THE DRAWER. 2. Acceptance by drawee converts it into a binding instrument. 3. Notarisation is needed only for noting on dishonour. 4. Hence (B) is required for validity. _Source: Maharashtra Balbharati Std XII Book-Keeping & Accountancy, Ch 7 "Bills of Exchange", §7.1 ¶§7.1_