To answer this question, you need to understand the layers of the OSI (Open Systems Interconnection) model. The OSI model is a conceptual framework used to understand how different network protocols and functions interact with each other.
Encryption is a process of converting plaintext into ciphertext to secure the data during transmission. This process typically takes place at the presentation layer, which is Layer 6 of the OSI model.
Let's go through each option to understand why it is correct or incorrect:
Option A) Application - This option is incorrect because the application layer (Layer 7) is responsible for providing network services to the user. It includes protocols such as HTTP, FTP, and SMTP but does not directly handle encryption.
Option B) Presentation - This option is correct because the presentation layer (Layer 6) is responsible for data encryption and decryption, as well as data compression and formatting. Encryption is one of the functions performed at this layer.
Option C) Session - This option is incorrect because the session layer (Layer 5) is responsible for establishing, managing, and terminating connections between applications. It does not directly handle encryption.
Option D) Data link - This option is incorrect because the data link layer (Layer 2) is responsible for the reliable transfer of data between network nodes. It does not directly handle encryption.
The correct answer is B) Presentation. This option is correct because encryption takes place at the presentation layer of the OSI model.