The answer is 2. See the last two lines on the same page that others have mentioned: https://docs.netapp.com/us-en/ontap/system-admin/quorum-epsilon-concept.html "A two-node cluster presents some unique challenges for maintaining quorum. Two-node clusters use cluster HA, in which neither node holds epsilon; instead, both nodes are continuously polled to ensure that if one node fails, the other has full read-write access to data, as well as access to logical interfaces and management functions."

B-2HA. 2node cluster does not need epsilon because if they are 2node, no any problem happens for system continuity. (1node fail, another node takes their jobs.) Epsilon has the role that is another shadow vote for quorum. When is it been needed ? Yeah, minimum 4node cluster = 2HA cluster need another vote because if 2nodes are down at the same time, 4nodes system cannot judge that their system is dead or alive without another vote, epsilon.

If the node that holds epsilon becomes unhealthy, takes over its high-availability partner, or is taken over by its high-availability partner, then epsilon is automatically reassigned to a healthy node in a different HA pair. BUT: A two-node cluster presents some unique challenges for maintaining quorum. Two-node clusters use cluster HA, in which neither node holds epsilon. So the answer is: 2 HA pairs to enable epsilon. https://docs.netapp.com/us-en/ontap/system-admin/quorum-epsilon-concept.html

B. If the node that holds epsilon becomes unhealthy, takes over its high-availability partner, or is taken over by its high-availability partner, then epsilon is automatically reassigned to a healthy node in a different HA pair https://docs.netapp.com/us-en/ontap/system-admin/quorum-epsilon-concept.html

A 1 HA pair

I think this is A. 1 HA pair Epsilon is automatically assigned to the first node when the cluster is created. If the node that holds epsilon becomes unhealthy, takes over its high-availability partner, or is taken over by its high-availability partner, then epsilon is automatically reassigned to a healthy node in a different HA pair. https://docs.netapp.com/us-en/ontap/system-admin/quorum-epsilon-concept.html