When someone is considering suicide, it's essential to approach the situation with care and support. Among the actions you listed, you should avoid:
B. Leave him alone to work it out.
Leaving someone alone who may be in crisis can be detrimental and may worsen their feelings of isolation or despair. Instead, it's important to reach out, communicate your concern, and provide a supportive presence. The other options (A, C, and D) involve being supportive, notifying someone who can help, and listening, which are all important actions to take. If you suspect someone is in immediate danger, it's crucial to take it seriously and seek professional help.