CIDR saves spaces on which of the following?

A.
routing tables

B.
routing racks

C.
address space

D.
domain names

Explanation:
The routing tables in the Internet have been growing as fast as the Internet and the router
technology specifically and computer technology in general has not been able to keep pace. In
December 1990 there were 2190 routes and 2 years later there were over 8500 routes. In July
1995 there are now over 29,000 routes, which require approximately 10 MB in a router with a
single peer. Routers at interconnection points (or multi-homed hosts doing full routing with many
peers) receive these routes from several peers, and need several dozen megabytes of RAM (and
the appropriate CPU horsepower) to handle this. A list of those routers that can handle this
appears at the end of this question. Routers with 64MB of memory have the capacity for
approximately 60,000 routes after which some routes will just have to be left out of the global
routing tables, and the more likely ones to be left out are routes covering small pieces of address
space. <br>Without the CIDRization work that has gone on for the past 2 years the routing tables
would be in excess of 65,000 routes. By CIDRizing you help the Internet reduce the routing
overload as well as increasing the liklihood that in the future your routes will be carried by all ISPs.