Which of the following is the right sequence of hooks that get called in AWS CodeDeploy?

Answer options:

A.Application Stop->BeforeInstall->After Install->Application Start
B.BeforeInstall->After Install-> Application Stop-> Application Start
C.BeforeInstall->After Install->Validate Service-> Application Start
D.BeforeInstall->Application Stop-> Validate Service-> Application Start

Answer - A
This is also mentioned in the AWS Documentation.
Options B and D are incorrect because the application needs to be stopped before doing the pre-install tasks such as decrypting files and creating a backup.
Option C is incorrect because ValidateService should be the last event. It is used to verify if the deployment is completed successfully. 
For more information on the hooks order, please refer to the below URL-
https://docs.aws.amazon.com/codedeploy/latest/userguide/reference-appspec-file-structure-hooks.html#reference-appspec-file-structure-hooks-run-order