A. The allocation of IP subnets is centrally controlled and maintained and this central database can be queried to see who owns a certain subnet, and also which companies own which subnets.
ARIN is the non-profit organization which maintains this database and provides a web based whois program at http://www.arin.net/whois/.
You can type in a subnet, e.g. 169.254 or a name, e.g. Microsoft.