Answer - A,B and D
The AWS Documentation the following products which can be integrated with Cloudwatch logs
1) Amazon Kinesis - Here data can be fed for real time analysis
2) Amazon S3 - You can use CloudWatch Logs to store your log data in highly durable storage such as S3.
3) Amazon Lambda - Lambda functions can be designed to work with Cloudwatch logs
For more information on Cloudwatch Logs, please refer to the below link:
http://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/WhatIsCloudWatchLogs.html