Analyze the following scenarios to determine if the described metric appropriately measures activation for the given type of consumer app:
- Scenario I: A language learning app tracks the number of lessons completed by users as its primary activation metric.
- Scenario II: A ride-sharing app considers the total time spent browsing the app as its key activation metric.
- Scenario III: A cooking app uses the number of recipes saved by users as the main measure of user activation.
- Scenario IV: A personal finance app measures activation by the frequency of users checking their account balances.
Identify which scenarios correctly match the app type with its activation metric.