When It Comes to Mixing Individual with Couple/family Therapy, the Textbook

When it comes to mixing individual with couple/family therapy, the textbook authors advocate which rule?

A) Once an individual client, always an individual client
B) Dual roles are an artifact of old ethics guidelines
C) Contemporary therapists should be able to navigate dual roles effectively
D) A client in the hand is worth two in the waiting room
E) Both B and C