What is the purpose of Classless Inter-Domain Routing (CIDR)?

A.
To allow for the traditional classes to be used more efficiently

B.
To extend the IP address space to 128 bits in size

C.
To provide more security for network traffic

D.
To allow for more efficient routing

Explanation:
Classless Inter-Domain Routing (CIDR) was created because it was clear
that available IP addresses were running out as more individuals and corporations
participated on the Internet. A class B address range is usually too large for most
companies, and a class C address range is too small. So CIDR provides the
flexibility to increase or decrease the class sizes as necessary.