The nurse demonstrates an understanding of the importance of assessment in prevention of mental illness when:
Correct Answer: A
Rationale: The correct answer is A because observing the partner of a pregnant woman for effective support and caring is important in preventing mental illness by promoting a supportive environment. This assessment can help identify potential risk factors or stressors that may contribute to the development of mental health issues. In contrast, options B, C, and D focus on interventions after the mental illness has already been diagnosed, rather than prevention through early assessment. B addresses managing a diagnosed condition, C focuses on treatment through counseling, and D involves evaluating specific symptoms rather than holistic support. Thus, A is the most appropriate choice for prevention through early assessment.