What is true about AS numbers when configuring EIGRP?$($Choose all that apply$)$

a$.$ AS numbers are managed by IANA and assigned by RIRs to ISPs, Internet Backbone providers, and institutions connecting to other institutions.

b$.$ AS numbers are needed to exchange routes between AS

c$.$ AS numbers can range from $0$ to $65535$

d$.$ All routers in the EIGRP domain does not have to use the same AS numbers