Thank you for reaching out in the community regarding the poll in your welcome email. I reviewed your account and I see the welcome email. However, I don't see that poll action block is added. Welcome emails will not provide any reporting data for action blocks including polls. You can use the click reports to determine which answer your customers have clicked on. Here is an article that will show you how to dot that:
You may want to consider creating a survey campaign instead of a poll, and provide a link to your survey in the welcome email. By setting it up that way, you'll be able to see the reporting for the responses in the survey campaign. Here are some articles about the survey campaign you may find helpful:
Please let us know if you have any further questions on this.