What is the basis for purchasing Cortex XDR licensing?

What is the basis for purchasing Cortex XDR licensing?
A . volume of logs being processed based on Datalake purchased
B . number of nodes and endpoints providing logs
C . unlimited licenses
D . number of NGFWs

Answer: B

Explanation: https://docs.paloaltonetworks.com/cortex/cortex-xdr/cortex-xdr-pro-admin/cortex-xdr-overview/cortex-xdr-licenses/migrate-your-cortex-xdr-license