Final answer:
Rust around wheel nuts may indicate that they are loose.
Step-by-step explanation:
The correct statement among the options provided is:
c. Rust around wheel nuts may mean that they are loose.
When rust forms around wheel nuts, it can indicate that they have been exposed to moisture for a long period of time or that they have not been properly tightened. As a result, they may become loose, leading to potential issues while driving. Rust can weaken the connection between the wheel nuts and the wheel, which can result in a dangerous situation.