What may happen if the gauge is left in the sun?

When a gauge is left in the sun, it is exposed to high temperatures and potentially harmful UV radiation. However, if the gauge is designed to operate under a range of environmental conditions, it should not inherently stop standardizing just because it has been in direct sunlight. Many gauges contain materials and components meant to withstand various weather conditions, so typical exposure to sunlight may not directly impair their functionality.

In contrast, extreme heat can affect some instruments, potentially leading to temporary alterations in readings or other performance issues. However, the phrasing of option C suggests that the gauge is functioning well within its design specifications regardless of sunlight exposure, which aligns with the expectation for a quality gauge.

It's important to consider that while being left in the sun can cause long-term degradation of some instruments, a well-constructed and maintained gauge should still be functional without needing immediate recalibration or showing a complete failure in standardization.