When selecting activities for observation, what factor is most important? a. The complexity of the activity. b. The duration of the observation period. c. The client's volition and motivation to participate. d. . The therapist's familiarity with the activity.

c. The client's volition and motivation to participate.<br /><br />The client's volition and motivation to participate are crucial factors when selecting activities for observation. This ensures that the client is engaged and willing to participate, which can lead to more accurate and meaningful observations.