Transport Layer Security (TLS) is architecturally composed of two primary layers. The lower layer is the TLS Record Protocol, which is responsible for securing application data using the parameters established during the handshake. The upper layer consists of three sub-protocols that manage the connection: the TLS Handshake Protocol, the Change Cipher Spec Protocol, and the Alert Protocol. The TLS Handshake Protocol is the most significant of these, as it is used by the client and server to authenticate each other, negotiate a cipher suite, and establish the shared secret keys that will be used for the session.

A. The Internet Protocol (IP) operates at the Network Layer (Layer 3) of the OSI model, whereas TLS operates above the Transport Layer (Layer 4).
B. This is a generic and inaccurate term. The TLS Record Protocol is the specific component that handles the fragmentation, compression, and protection of application data.
C. A "Link Protocol" refers to the Data Link Layer (Layer 2). TLS does not operate at this layer; it is a higher-level protocol.

1. Dierks, T., & Rescorla, E. (2008). The Transport Layer Security (TLS) Protocol Version 1.2. IETF. RFC 5246. Section 6, "TLS Protocols," states: "At the core of the TLS protocol is the TLS Record Protocol... The TLS Handshake Protocol is layered on top of the TLS Record Protocol."

2. Rescorla, E. (2018). The Transport Layer Security (TLS) Protocol Version 1.3. IETF. RFC 8446. Section 2, "Protocol Overview," describes the layered architecture: "At the lowest level, the Record Protocol... At the highest level, the following four protocols are defined: the Handshake Protocol, the Alert Protocol, the Change Cipher Spec Protocol, and the Application Data Protocol."

3. Kurose, J. F., & Ross, K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson. In Chapter 8.3, "Securing TCP Connections: TLS," the text describes the two main sub-protocols: "The TLS Record Protocol" and "The Handshake Protocol."