Which of the following is an example of an analog communication method or medium capable of carrying analog signals?

Introduction / Context:
Analog communication conveys information using continuously varying signals such as amplitude, frequency, or phase. Many physical media and carriers can support analog modulation schemes, including light and radio-frequency paths as well as wired lines.

Given Data / Assumptions:

• We are identifying media/methods that can carry analog signals.
• Examples include optical, RF/microwave, and legacy telephony wiring.
• Question asks whether each given example qualifies.

Concept / Approach:
In practice, a “method” or “medium” is analog-capable if it can transport a waveform whose amplitude/phase/frequency vary continuously. Many channels can carry either analog or digitally modulated signals; capability for analog is the key.

Step-by-Step Solution:
1) Laser beam: Light intensity or phase can be analog-modulated (e.g., AM, FM, PM of an optical carrier).2) Microwave: RF carriers are classically used with analog FM/AM/PM; microwave links historically carried analog TV and voice.3) Voice grade telephone line: Designed originally for analog voice (300–3400 Hz) and supports analog modems.4) Therefore, all listed items are valid analog-capable communication methods/media.

Verification / Alternative check:
Historical deployments (analog TV over microwave, analog telephony, optical analog links) confirm analog carriage on all three media.

Why Other Options Are Wrong:
None of the above: Incorrect because each listed medium can carry analog signals.

Common Pitfalls:
Assuming lasers and microwaves are “digital only.” The modulation format (analog vs digital) is a choice; the medium often supports both.

Final Answer:
All of the above