Reference Material:

https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/dns-failover-types.html#dns-failover-types-active-passive:
"Use an active-passive failover configuration when you want a primary resource or group of resources to be available the majority of the time and you want a secondary resource or group of resources to be on standby in case all the primary resources become unavailable"
https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/routing-policy.html:
"Failover routing lets you route traffic to a resource when the resource is healthy or to a different resource when the first resource is unhealthy. The primary and secondary records can route traffic to anything from an Amazon S3 bucket that is configured as a website to a complex tree of records. "
Answer is A