Which two operations should you monitor?

You are maintaining an application that uses the Azure Content Delivery Network (CDN) to serve terabytes of
content that is stored in page blobs.
Your bill for CDN services is higher than you expect.
You need to monitor the application to find issues that increase costs.
Which two operations should you monitor? Each correct answer presents part of the solution.

A.
The Time-To-Live (TTL) of the blobs.

B.
The country of origin for the client computer and the CDN region.

C.
The number of requests that result in an HTTP status code over 400.

D.
The allocated size of page blobs.

E.
The expiration date of the blobs.