Multicast is a method of data transmission in which a single stream of data is sent from a source to multiple destinations simultaneously. This technique is especially useful in video surveillance because it allows multiple viewers to receive the same video stream without duplicating the data sent across the network. In other words, the video stream only needs to be sent once from the camera, even though there are multiple viewers, reducing network bandwidth usage. This makes option C correct. For more detailed information, refer to Axis Communications' official documentation on network video fundamentals and multicast usage.

Axis cameras offer several advanced focus technologies to enhance image clarity and ease of use. Focus Pinpoint allows for precise manual focus adjustments, ensuring sharpness in critical areas. Focus Recall enables cameras to remember and quickly return to pre-set focus positions, which is useful for surveillance scenarios where the camera frequently moves between different points of interest. According to Axis documentation, these technologies are designed to improve the accuracy and efficiency of camera setup and operation.

The main benefit of using Power over Ethernet (PoE) is cost reduction in installation. PoE allows network cables to carry both data and power, eliminating the need for separate power lines and reducing the amount of cabling required. This simplifies installation, reduces material costs, and allows greater flexibility in camera placement. Axis Communications notes that PoE significantly cuts down on installation expenses by streamlining the infrastructure needed for network devices.

"M12 lenses are easily recognized by their small size and the thread on the lens barrel. The M12 refers to the metric thread diameter (12 mm), which is much smaller than C/CS-mount lenses. These are often used in compact and modular camera models."
- Axis Communications Academy, Network Video Fundamentals, 2022
"M12-mount lenses are also called 'board lenses' and are screwed directly into the camera's sensor module."
- Axis M12 Lens Accessories Guide
References:
Axis Communications Academy, Network Video Fundamentals, 2022 (p. 33)
Axis Lens Accessories - M12 Lenses

"Adjusting the white balance setting can correct color inaccuracies caused by different lighting conditions, such as the orange tint seen under sodium-vapor street lamps."
- Axis Communications Academy, Network Video Fundamentals, 2022
"White balance ensures that white objects are rendered as white in the image, improving overall color fidelity."
- Axis White Balance Technical Guide
References:
Axis Communications Academy, Network Video Fundamentals, 2022 (p. 24)
Axis Technical Note: White Balance