The correct answer is A. HTTP.
HTTP (Hypertext Transfer Protocol) is an application-level protocol that defines how messages are formatted and transmitted between a client and a server. It is the protocol used by the World Wide Web to transfer hypertext documents and other web resources between web servers and web browsers.
HTTP supports URIs (Uniform Resource Identifiers) and MIME types (Multipurpose Internet Mail Extensions). URIs are used to identify resources on the web, and MIME types are used to specify the type of data that is being transferred.
UDP (User Datagram Protocol) is a connectionless protocol that is used to send datagrams (packets of data) between hosts. It is a simpler protocol than TCP (Transmission Control Protocol), and it is often used for applications that do not require a reliable connection, such as streaming media.
CoAP (Constrained Application Protocol) is a lightweight protocol that is designed for use in resource-constrained devices, such as sensors and actuators. It is based on the same principles as HTTP, but it is optimized for low-power and low-bandwidth networks.
SPI (Secure Sockets Layer) is a cryptographic protocol that is used to secure communications between two hosts. It is often used to secure web traffic, but it can also be used to secure other types of communications, such as email and file transfers.