Doug has created a VPC with CIDR 10.201.0.0/16 in his AWS account. In this VPC he has created a public subnet with
CIDR block 10.201.31.0/24. While launching a new EC2 from the console, he is not able to assign the private IP address
10.201.31.6 to this instance. Which is the most likely reason for this issue?

A.
Private IP address 10.201.31.6 is not part of the associated subnet’s IP address range.

B.
Private IP address 10.201.31.6 is blocked via ACLs in Amazon infrastructure as a part of platform security.

C.
Private address IP 10.201.31.6 is currently assigned to another interface.

D.
Private IP address 10.201.31.6 is reserved by Amazon for IP networking purposes.

Explanation:
In Amazon VPC, you can assign any Private IP address to your instance as long as it is:
Part of the associated subnet’s IP address range
Not reserved by Amazon for IP networking purposes
Not currently assigned to another interface
http://aws.amazon.com/vpc/faqs/