which method is used by Cisco WLC v7.0 for the autoinstall process?

CAPWAP discovery broadcast is a method, but it is typically limited to Layer 2 and is one of several discovery mechanisms, not the sole autoinstall process.

Storing the IP address in NVRAM is a manual AP priming method, not an 'autoinstall' process where the AP discovers the controller itself.

DNS resolution of 'cisco-capwap-controller' is a valid CAPWAP discovery method but is not the specific method identified as correct for this question.

DHCP Option 150, typically used for TFTP server discovery, is also supported by Cisco lightweight Access Points (APs) for discovering the IP address of the Wireless LAN Controller (WLC) during the initial autoinstall or CAPWAP discovery process, particularly in older or specific WLC v7.0 deployments.

DHCP Option 43 is a very common and often preferred method for providing WLC IP addresses, but for this specific question's context and answer, Option 150 is the identified correct method.

DHCP Option 60 is used as a 'Vendor Class Identifier' by clients to identify themselves to the DHCP server, not for providing WLC IP addresses.