Which of the following is NOT a recognized protocol for data transmission?

The correct answer is the option that identifies a non-recognized protocol for data transmission. Although HTTP is a well-known protocol, primarily used for accessing and delivering web pages, it is clearly recognized for data transmission across the internet.

In contrast, the other options are specific protocols that have been developed for particular purposes in data transmission within financial and electronic trading contexts. For example, FIX (Financial Information eXchange) is widely utilized for real-time electronic trading and communications in the financial markets. FAST (FIX Adapted for Streaming) is an encoding specification that enhances the transmission efficiency of FIX messages. Similarly, ITCH is a protocol used for delivering market data in a high-speed manner, particularly useful in trading scenarios.

Therefore, the selection of HTTP as a non-recognized protocol in the context of this question stems from the understanding that it is indeed recognized, whereas the other options are tailored protocols specifically developed for specialized financial applications.