Answer - A and B.
This is mentioned in the AWS Documentation.
By default, an alias points to a single Lambda function version.
When the alias is updated to point to a different function version, incoming request traffic instantly points to the updated version.
This exposes that alias to any potential instabilities introduced by the new version.
To minimize this impact, you can implement the routing-config parameter of the Lambda alias that allows you to point to two different versions of the Lambda function and dictate what percentage of incoming traffic is sent to each version.
Options C and D are incorrect since you need to use ALIAS for this purpose.
Option E is incorrect because A & B are the correct ways to achieve the requirement.