REST (Representational State Transfer) is a widely adopted architectural style for designing networked applications and web services. It is not a protocol in the strictest sense but a set of constraints and principles that use standard protocols like HTTP. In the context of web services, REST is considered a primary approach, often contrasted with the SOAP protocol. It leverages standard HTTP methods (GET, POST, PUT, DELETE) to create stateless, scalable, and maintainable web services. Its simplicity and alignment with the web's architecture have made it a common choice for modern APIs.

A. SOAK: This is not a recognized web service protocol. It is likely a typographical error for SOAP (Simple Object Access Protocol), which is a valid, albeit different, web service protocol.

C. HTTP: HTTP (Hypertext Transfer Protocol) is the foundational application-layer protocol that RESTful web services use for communication. It is the transport mechanism, not the web service architectural style itself.

D. RTE: This is not a standard acronym for a web service protocol. It may refer to concepts like "Runtime Environment," which are unrelated to web service communication standards.

1. Fielding

R. T. (2000). Architectural Styles and the Design of Network-based Software Architectures. Doctoral dissertation

University of California

Irvine. Chapter 5 defines REST as an architectural style. Retrieved from https://www.ics.uci.edu/~fielding/pubs/dissertation/restarchstyle.htm

2. W3C (World Wide Web Consortium). (2004). Web Services Architecture. W3C Working Group Note. Section 1.3.2 discusses REST as a prominent architectural style for web services. Retrieved from https://www.w3.org/TR/ws-arch/#id2260802

3. Pautasso

C.

Wilde

E.

& Alarcon

R. (2014). REST: Advanced Research Topics and Practical Applications. In Web Engineering (pp. 1-11). Springer

Berlin

Heidelberg. This paper discusses REST as a "lightweight alternative to SOAP/WSDL/WS- based Web services." (Page 1).