Your question is Acquisition and Retention Feature Test. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You are testing a new product feature that could influence both top-of-funnel acquisition and downstream retention. The feature may make the product more appealing to new users, but it could also change the quality of users who sign up or alter early product experience in ways that affect whether they come back.
How would you design an experiment for this feature so you can measure its impact on both acquisition and retention? Explain how you would choose the primary metric, guardrails, randomization approach, and decision rule given that the feature affects multiple stages of the user journey.