Which of the following is the logical progression in internal private cloud adoption?

Which of the following is the logical progression in internal private cloud adoption?
A. Virtualize, PaaS, IaaS and SaaS
B. SaaS, PaaS, IaaS and Virtualize
C. Virtualize, IaaS, PaaS and SaaS
D. IaaS, PaaS, Virtualize and SaaS

Correct Answer: C
Explanation/Reference:
Explanation:
Cloud computing service models arranged as layers in a stack.

References: https://en.wikipedia.org/wiki/Cloud_computing#Service_models