The correct answer is option 'A' - 106 to 108 Hz.

Coaxial cables are commonly used in local area networks (LANs) to transmit data signals. These cables consist of an inner conductor, an insulating layer, a metallic shield, and an outer conductor. The frequency range at which coaxial cables are used depends on their design and specifications.

Here is an explanation of why option 'A' is the correct answer:

1. LAN Coaxial Cables:
LANs typically use Ethernet cables to connect computers and other devices within a local network. Coaxial cables are one of the types of Ethernet cables used in LANs, along with twisted pair cables and fiber optic cables.

2. Frequency Range for Coaxial Cables:
The frequency range at which coaxial cables are used depends on various factors including the cable's construction, impedance, and the type of signals being transmitted. Coaxial cables can support a wide range of frequencies, from low frequencies used for audio signals to high frequencies used for data transmission.

3. LAN Data Transmission:
In LANs, data is transmitted using digital signals. These signals are typically in the form of square waves, with a combination of high and low voltage levels representing binary data. The frequency of these square waves is determined by the data rate or the bandwidth required for the transmission.

4. LAN Data Rates:
LANs typically operate at data rates ranging from a few megabits per second (Mbps) to several gigabits per second (Gbps). The data rate determines the frequency range required for the transmission.

5. LAN Coaxial Cable Specifications:
Coaxial cables used in LANs are typically designed to support data rates of up to 100 Mbps or 1 Gbps, depending on the specific LAN technology being used (e.g., Ethernet, Fast Ethernet, Gigabit Ethernet). These cables are designed to have a characteristic impedance of 50 or 75 ohms, depending on the LAN standard.

6. Frequency Range for LAN Coaxial Cables:
Based on the LAN data rates and the characteristic impedance of LAN coaxial cables, the frequency range at which these cables are used can be determined. For LANs operating at data rates of up to 100 Mbps or 1 Gbps, the frequency range is typically in the range of 106 to 108 Hz.

Conclusion:
The frequency range at which LAN coaxial cables are used is in the range of 106 to 108 Hz. This range is suitable for transmitting digital signals at data rates of up to 100 Mbps or 1 Gbps, which are commonly used in LANs.