An administrator can attach a baseline to which two inventory objects?

The correct choice involves ESXi hosts because in VMware vSphere, baselines are primarily used to manage and ensure compliance for ESXi hosts. When you attach a baseline to an ESXi host, you can check that host against the baseline for compliance with desired software and configuration states. This process helps in managing updates, patches, and custom configurations, thus maintaining a secure and efficient virtual environment.

Resource pools typically serve as divisions of compute resources among virtual machines and do not directly relate to baseline compliance processes. Similarly, datastores are used for storage purposes and are not intended for attaching baselines. Data centers represent logical structures for managing multiple ESXi hosts and resources, but they do not have a direct use for baselines in the same way individual hosts do. Therefore, the focus on ESXi hosts as the primary inventory object for baseline attachment is essential for effective lifecycle management in a vSphere environment.