Arbitrage derivatives are not a recognized category of over-the-counter (OTC) derivatives. Arbitrage is a strategy used in trading and investing that seeks to exploit price differences of a single asset or similar assets in different markets or in different forms. It is not a type of derivative but a strategy that can be applied across various types of derivatives. The main categories of OTC derivatives are interest rate derivatives, foreign exchange derivatives, equity derivatives, commodity derivatives, and credit derivatives. These derivatives are traded over-the-counter, meaning they are traded directly between two parties without going through an exchange. Each category of OTC derivatives has its own unique characteristics and risks, and they are used for a variety of purposes such as hedging, speculation, and arbitrage. Therefore, the term 'arbitrage derivatives' is a misnomer as it conflates a trading strategy (arbitrage) with a type of financial instrument (derivatives).

Why the other options are incorrect:

• Choice A is incorrect. Interest rate derivatives are a recognized category of OTC derivatives. They are contracts whose value is derived from one or more interest rates, financial instruments, or indices of interest rates.
• Choice B is incorrect. Exchange rate derivatives are also a recognized category of OTC derivatives. These types of contracts derive their value from the performance of underlying exchange rates between two currencies.
• Choice C is incorrect. Credit derivatives are another recognized category of OTC derivatives. These financial instruments derive their value from the credit risk on an underlying loan or bond.