**Core Concept**
Ergonomics is the science of designing and arranging systems, objects, and environments to minimize stress and discomfort on humans. In the context of workstations, ergonomic design aims to reduce the risk of musculoskeletal disorders, including neck problems, by promoting proper posture and movement.

**Why the Correct Answer is Right**
The correct answer is related to the concept of ergonomics and its application in designing workstations to prevent neck problems. The use of a table top on desks is an example of ergonomic design, as it allows users to maintain a neutral spine position and avoid straining their necks while working. This design feature helps to reduce the risk of musculoskeletal disorders, such as neck pain and discomfort.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not relate to ergonomic design or the prevention of neck problems. While a standing desk may be beneficial for overall health, it is not directly related to the specific design feature of a table top on a desk.
**Option B:** This option is incorrect because it is unrelated to ergonomic design or the prevention of neck problems. A keyboard tray may be useful for reducing strain on the wrists and hands, but it does not address neck problems specifically.
**Option C:** This option is incorrect because it is unrelated to ergonomic design or the prevention of neck problems. A footrest may be useful for reducing strain on the legs and feet, but it does not address neck problems specifically.

**Clinical Pearl / High-Yield Fact**
A well-designed ergonomic workstation can reduce the risk of musculoskeletal disorders by up to 50%. This highlights the importance of incorporating ergonomic design principles into the design of workstations to promote worker health and well-being.

**Correct Answer:** C.