How can the domain’s zone apex, for example, “myzoneapexdomain.com”, be pointed
towards an Elastic Load Balancer?

A.
By using an Amazon Route 53 Alias record

B.
By using an AAAA record

C.
By using an Amazon Route 53 CNAME record

D.
By using an A record

Explanation:
You can create an alias resource record set at the zone apex.
You cannot create a CNAME record at the top node of a DNS namespace, also known as the
zone apex.
For example, if you register the DNS name example.com, the zone apex is example.com.
http://docs.aws.amazon.com/Route53/latest/DeveloperGuide/resource-record-sets-choosingalias-non-alias.html