Combatant commands use a phased approach when planning for a wide spectrum of operations. Which phase is characterized by a "rapid response to maintain the public trust and mitigate suffering and save lives?"

Phase II - Respond

Explanation:

The Phase II - Respond is a phase which is characterized by a "rapid response to maintain the public trust and mitigate suffering and save lives"!

It's a phased approach used in combatant commands when planning for a wide spectrum of operations. It's aim is to alleviate suffering and save lives.