Which statement best describes the relationship between Flex Clusters and Flex ASM? 

There is no relationship, except that both have "Flex" in their names. 

A Flex Cluster requires Flex ASM, but Flex ASM does not require a Flex Cluster. 

Flex ASM requires a Flex Cluster, but a Flex Cluster does not require Flex ASM. 

Flex Clusters and Flex ASM always require each other.