The correct answer is D. All of these.
A negotiable instrument is a document that can be easily transferred from one person to another. It is a written promise to pay a certain amount of money to the bearer of the instrument. Negotiable instruments are governed by the Negotiable Instruments Act, 1881.
A promissory note is a written promise to pay a certain amount of money to the bearer of the note. The note must be signed by the maker, and it must contain an unconditional promise to pay.
A bill of exchange is an order written by one person (the drawer) to another person (the drawee) to pay a certain amount of money to a third person (the payee). The bill must be signed by the drawer, and it must contain an unconditional order to pay.
A cheque is a bill of exchange drawn on a bank. It is a written order to the bank to pay a certain amount of money to the bearer of the cheque. The cheque must be signed by the drawer, and it must contain an unconditional order to pay.
Negotiable instruments are important because they allow for the easy transfer of money. They are also used in many types of financial transactions, such as loans and investments.