Fill in the blank: Each cluster has __________ interfaces.

A. Five

B. Two

C. Three

D. Four

Explanation: Each cluster member has three interfaces: one external interface, one internal interface, and one for synchronization. Cluster member interfaces facing in each direction are connected via a switch, router, or VLAN switch.

Reference: https://sc1.checkpoint.com/documents/R76/CP_R76_ClusterXL_AdminGuide/7292.htm