Can anyone give an answer and explain the reason, please? Thank you so much.

* The role of the CDN provider's authoritative DNS name server in a content distribution network, simply described, is: a) to provide an alias address for each browser access b) to map the query for each CDN object to the CDN c) to provide a mechanism for CDN "origin servers" to d) none of the above, CDN networks do not use DNS to the "origin server" of a CDN website server closest to the requestor (browser) provide paths for clients (browsers)