Which of the following is a sign of a possible LP gas leak?

A strong, unpleasant odor is indeed a sign of a possible LP gas leak. This odor is intentionally added to propane during production to ensure safety, as propane is normally odorless. The distinctive smell is often described as similar to rotten eggs, making it relatively easy for individuals to detect leaks quickly. Being aware of this odor is crucial, as the ability to smell leaks can significantly reduce the risks associated with gas exposure, including fire hazards and health risks from inhalation.

The other options do not indicate a possible gas leak. An increase in pressure readings could suggest normal operation or a different issue within the system but does not directly indicate a leak. Clear, blue flames indicate that the LP gas is burning correctly and efficiently, which is a sign of proper combustion, not a leak. Low humidity levels are unrelated to gas leaks and do not serve as an indicator for detecting propane issues. Understanding these distinctions is important for safety and effective monitoring of LP gas systems.