Which of the following statements is true of family rules?​

A) ​They are always openly acknowledged.
B) ​They destroy a family's equilibrium.
C) ​They do not affect the sequence of interactions to an event.
D) ​They govern the range of behavior in the family system.

Family rules are guidelines or expectations for behavior that are established within a family system. These rules govern the range of behavior in the family and help to create structure and stability. While not all family rules are openly acknowledged or discussed, they do impact the interactions and dynamics within the family system. Therefore, option D is the correct statement.