Answer: had managed.
Explanation: Verb tenses are clues to help us figure out when the action in a sentence is happening. Verbs come in three tenses: past, present, and future. The past is used to describe things that have already happened. The present tense is used to describe things that are happening right now, or things that are continuous. And the future is used to describe things that will happen. The past perfect tense of the verb "managed" is "had managed."