"And at our time?"
Translation:Und zu unserer Zeit?
Turns out it means none of those things. I looked up some other examples of when this is used and it makes it a lot clearer: https://context.reverso.net/translation/german-english/zu+unserer+Zeit
If only Duolingo had given us one of these examples, such as: Zu unserer Zeit war es anders. = It was different in our day.
It's because "zu" is a dative preposition. Since "Zeit" is a feminine singular noun, the possessive pronoun modifying it must have the dative feminine singular ending, which is "er".
Dative endings are: masculine and neuter singular = em; feminine singular = er; all plurals = en.