Answer: "I feel so bad for them and I would want someone to help me if I were them."
Explanation: Prosocial thinking involves thought that tends toward contributing to a beneficial outcome by negotiation, problem solving, problem analysis, clarification, or respectful behaviors. This includes feeling empathy and concern for others and behaving in ways to help or benefit other people.
Since Prosocial thinking involves the feeling of empathy which is Identification with or understanding of the thoughts, feelings, or emotional state of another person, the best option is "I feel so bad for them and I would want someone to help me if I were them." Because it involves the individual putting their self in others shoes.