Which of the following could cause this issue?

An administrator is configuring an ESX Host to boot from SAN. After entering the HBA BIOS and attempting to select a boot LUN, the ESX Host becomes unresponsive. Which of the following could cause this issue?

Answer: The HBA BIOS sees too many devices in the SAN Zone

Explanation:

If a large number of initiator or target storage devices are in the same SAN zone with the ESX Host, the HBA BIOS may become unresponsive. If the target storage device was not visible, the LUN could not be selected, but the BIOS availability would be unaffected.