💡 Detailed Explanation
The phrase '〜どうにかならなかったものかね' expresses regret or dissatisfaction about a past event. The speaker is not asking for a solution but is venting his frustration. The correct response shows agreement and empathy with this feeling. 'ええ、まったくです。もう少し誠意を見せてほしかったですね。' (Yes, exactly. I wish they had shown a bit more sincerity.) does this perfectly. The other options misunderstand the nuance: one incorrectly answers as if it were a simple past-tense question, and the other mistakes the venting for a direct order to take action.