You serve as a KMS Key Administrator for your company department. A KMS customer master key (CMK) with imported key material is about to expire. You need to use the same key material in the CMK and the application should use the same CMK. Which option should be used to rectify this situation?

Answer options:

A.Navigate to the AWS KMS in the management console. Locate the KMS CMK with the Origin value of EXTERNAL. In the Key Material section, update the Expiration Date.
B.Encrypt the same key material and reimport the key material to the same CMK.
C.Generate a new key material. Download the wrapping key and import token. Encrypt the key material and import the key material into the KMS CMK.
D.Create a new KMS CMK. Download the wrapping key and import token. Encrypt the key material and import the key material into the new KMS CMK.

Answer: B
Option A is incorrect because you can change the expiration date of a KMS key only by reimporting the same key material and specifying a new expiration date.
Option B is CORRECT because to change the expiration date of a KMS key, you must reimport the same key material and specify a new expiration date.
Option C is incorrect because you cannot import different key materials into a CMK.
Option D is incorrect because you should not use a new CMK as the same CMK needs to be used by the application.
Reference:
https://docs.aws.amazon.com/kms/latest/developerguide/importing-keys.html
https://docs.aws.amazon.com/kms/latest/APIReference/API_ImportKeyMaterial.html