Which of the following is the nominal or face value of a security?

The nominal or face value of a security refers to the value assigned to that security as stated by the issuer, typically reflecting the amount that will be paid back to the investor at maturity, or the price at which shares are issued. Par value, often used in the context of bonds, is the principal amount that the issuer agrees to pay the bondholder at maturity. For stocks, par value may not have the same significance in terms of actual market value but it still represents the official value assigned to the stock when it is issued.

In contrast, the other options like share, net, and market refer to different concepts. The term "share" relates to ownership in a company, "net" is often used to describe an amount after deductions (like taxes or expenses), and "market" pertains to the current trading price of the security in the marketplace. Therefore, "par" is the term that most accurately describes the nominal or face value of a security.