Final answer:
The correct option is c) Both (a) and (b). In-App Purchase and Ad Revenue are the options that can help monetize a free app.
Step-by-step explanation:
The correct option is c) Both (a) and (b). In-App Purchase and Ad Revenue can both be used to monetize a free app.
In-App Purchase allows users to make purchases within the app, such as unlocking additional features or content. This can generate revenue for the app developer. Ad Revenue is earned by displaying commercials or promotions from various advertisers within the app. Both methods are widely used in the industry and can be very effective if implemented correctly.
Ad Revenue is generated by displaying advertisements within the app. Advertisers pay the app developer for displaying their ads to the app's users.