Explanation
A reservation guarantees to a cloud customer that they will have access to a minimal level of resources to run their systems, which will help mitigate against DoS attacks or systems that consume high levels of resources.
A reservation pertains to memory and CPU resources. Under the concept of a reservation, memory and CPU are the guaranteed resources, but storage and networking are not included even though they are core components of cloud computing. Software would be out of scope for a guarantee and doesn't really pertain to the concept.

Explanation
Explanation:
The four possible approaches to risk are as follows: accept (do not patch and continue with the risk), avoid (implement solutions to prevent the risk from occurring), transfer (take out insurance), and mitigate (change configurations or patch to resolve the risk). Each of these answers contains at least one incorrect approach name.

Explanation/Reference:
Explanation:
A retina scan could be used in conjunction with an RSA token because it is a biometric factor, and thus a different type of factor. An access card, RFID, and USB thumb drive are all items in possession of a user, the same as an RSA token, and as such would not be appropriate.