Final answer:
Chuck's action of going to the Moore's house to reveal someone's location or activities is best described as informing, which is the act of giving information or apprising someone.
Step-by-step explanation:
Rusty reveals that Chuck figured out she wasn't at WJ's and went over to the Moore's house and told him. The action that Chuck took can best be described as informing. He informed someone about another person's location or activities. This is not considered lying, gossiping, or pranking.
The context of the action is important, but based on the verb used, 'told', it suggests a straightforward communication of facts rather than spreading rumors or deceiving someone.