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

A.
There is no relationship, except that both have “Flex” in their names.

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

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

D.
Flex Clusters and Flex ASM always require each other.

Explanation:
http://www.slideshare.net/ghanshyamkhetan/oracle-flex-asm-flex-cluster29360658(slide
9)