The correct answer is D because Cloud Datastore offers a NoSQL solution that is well-suited for storing the product catalog, especially given the limited data size.

• Option A is incorrect as Cloud SQL is a relational database service, not a NoSQL option.
• Option B is incorrect because Cloud Memorystore is designed for in-memory data storage, ideal for application caches requiring sub-millisecond access, not for a product catalog.
• Option C is incorrect since Bigtable, while a NoSQL database, is optimized for large-scale analytical and operational workloads, making it overkill for this scenario.