Final answer:
Indirect attacks refer to a tactic used in warfare to attack the enemy without directly engaging them. In the context of firefighting, it can involve strategically constructing control lines away from the fire's edge to contain and control its spread.
Step-by-step explanation:
Indirect attacks refer to a tactic used in warfare to attack the enemy without directly engaging them. In the context of the question, options A and B are unrelated to indirect attacks. Option C, 'Line always constructed during low to moderate fire behaviour,' could be seen as an indirect approach to fighting wildfires. Instead of attacking the fire head-on, firefighters strategically construct control lines away from the fire's edge to contain and control its spread.