💡 Detailed Explanation
The speaker is very politely and indirectly asking for help. The key phrases are 'お力添えなくしては' (without your help) and 'いかんともしがたい' (it's impossible to do anything). He is clearly stating that he needs 'Yamada-san's' help. The correct response is to acknowledge the request and agree to help. Response 1, 'Of course, if it's something I can do,' is a standard and polite way to accept. Response 2 ignores the implied request for help. Response 3 misunderstands who is asking for help.