Choose a precise A/B test primary metric

Imagine a mobile app is running an experiment in which the sole change is the color of the main call-to-action button on its home screen. You must choose exactly one primary metric for this A/B test and justify that choice without hedging. Your response must cover all five points below: Give the precise definition of the metric: numerator, denominator, unit of analysis (user or session), inclusion and exclusion rules for new users, returning users, employees, and testers,…