Which services allow the customer to retain full administrative privileges of the underlying EC2 instances?

B & C Elastic Load Balancing, AWS Elastic Beanstalk,

https://aws.amazon.com/elasticbeanstalk/faqs/

AWS Elastic Beanstalk, developers retain full control over the AWS resources powering their application. If developers decide they want to manage some (or all) of the elements of their infrastructure, they can do so seamlessly by using Elastic Beanstalk’s management capabilities.

https://aws.amazon.com/ec2/faqs/

It provides you with complete control of your computing resources and lets you run on Amazon’s proven computing environment. Amazon EC2 reduces the time required to obtain and boot new server instances to minutes, allowing you to quickly scale capacity, both up and down, as your computing requirements change. Amazon EC2 changes the economics of computing by allowing you to pay only for capacity that you actually use.

A, C are correct. There is no root access to ELB’s, RDS, or Elasticache

A & C – see above from Chef and others

A,C
Only the below services provide Root level access
* EC2
* Elastic Beanstalk
* Elastic MapReduce – Master Node
* Opswork