Answer:
- Express empathy for Chelsea.
Explanation:
As per the given situation, the most appropriate action for David to take right now would be to 'express empathy for Chelsea' as this would assist him to understand her state of mind and emotions and develop a connection with her which would help Chelsea overcome her feelings of isolation and lack of support after the argument. David needs to regulate his own feelings and attempt to sense her feelings and respond accordingly so that she would be able to share the cause of her this feeling and provide her comfort and satisfaction. Therefore, 'expression of sympathy' would be the best 'course of action' that David should take.