The suggested answer is D, E.
For integration testing that requires about 2 GB of data storage, the best environments are the Partial Sandbox and the Developer Pro Sandbox. The Developer Sandbox and Developer Edition are too limited in storage capacity, with the Developer Sandbox having only 200 MB and the Developer Edition having only 5 MB of storage. The Full Sandbox would be overkill as it is intended for production data replication and usually used for performance and load testing scenarios. Therefore, the Partial Sandbox, which provides a subset of production data with up to 5 GB of storage, and the Developer Pro Sandbox, which offers 1 GB of storage, are suitable for this integration testing.