The correct answer is c) WAN (Wide Area Network).

A Wide Area Network (WAN) is a network that connects multiple smaller networks over a large geographic area, such as cities, countries, or even continents. It uses dedicated high-speed telephone lines or other similar connections to facilitate communication between the different networks or network devices.

Here is a detailed explanation of why the correct answer is WAN:

1. Understanding the elements of the question:
- Network: A network refers to a collection of interconnected devices (computers, servers, printers, etc.) that can communicate and share resources.
- Separated by some distance: The network elements are physically located at different locations, which can be far apart.
- Two or more small networks: There are multiple local networks or LANs that need to be interconnected.
- Dedicated high-speed telephone lines: WANs often use dedicated lines, leased lines, or other high-speed connections to ensure efficient and reliable communication.

2. Local Area Network (LAN):
- LAN is a network that covers a small geographical area, typically within a building or a campus.
- LANs are commonly used in homes, offices, schools, or small businesses.
- LANs usually utilize Ethernet cables, Wi-Fi, or other local connections to connect devices within a limited area.
- They are designed for high-speed communication and resource sharing within a specific location.

3. Wide Area Network (WAN):
- WAN is a network that spans a wide geographic area, connecting multiple smaller networks.
- It is used to establish communication between LANs or other network devices across different locations.
- WANs can be used to connect offices in different cities, branches of a company in different countries, or even different countries altogether.
- WANs typically employ dedicated high-speed telephone lines, leased lines, or other connections to ensure reliable and efficient communication.
- They allow for the transmission of large amounts of data over long distances.

4. Explanation of the answer:
- Based on the given information, the network elements are separated by some distance, indicating that they are not located within the same physical area.
- The question also mentions the involvement of two or more small networks, suggesting the need to connect these smaller networks.
- Finally, the question specifies the use of dedicated high-speed telephone lines, which is a characteristic feature of WANs.
- Hence, the correct answer is c) WAN (Wide Area Network) as it perfectly fits the given description of a network whose elements may be separated by some distance, involving two or more small networks, and utilizing dedicated high-speed telephone lines.