Which of the following factors is typically a concern for both copper cables and optical fiber systems?

The concern regarding the physical environment is pertinent to both copper cables and optical fiber systems because both types of cabling can be affected by environmental conditions. Factors such as temperature fluctuations, humidity, exposure to moisture, and physical stress from bending or pulling can impact the performance and longevity of the cables.

For copper cables, the physical environment can lead to corrosion, changes in electrical resistance, or attenuation due to temperature or moisture, which affects the signal quality. For optical fiber, environmental conditions like temperature changes can cause expansion or contraction of the fiber, potentially leading to micro-bending or macrobending that affects signal transmission.

Considering these aspects, it's crucial for installation and maintenance to take into account the physical environment to ensure reliable system performance.