How do you respond to "Who will take care of you when you're old?"

I (35M) tend to hear this from my family and others as a reason we (my wife and I) should have kids.<br><br>What are the best responses to this?<br>Can I actually get some tech help? It's too early in the morning for my feeble mind.<br><br>&#x200B;<br><br>Edit: Wow! Thanks for all the great responses so far.