How do you ask participants if they have questions or feedback in Spanish?

The choice that best captures a polite and comprehensive way to ask participants if they have questions or feedback is "¿Tienen alguna pregunta o comentario?" This phrase directly translates to "Do you have any questions or comments?" and is effective because it explicitly invites participants to express both inquiries and feedback in a manner that is clear and respectful.

Using "alguna" adds an inclusive tone, making participants feel more comfortable in engaging with their thoughts, whether they're uncertain about something or have feedback to share. This phrasing also encompasses both aspects—questions and comments—making it a broad and inviting approach to gathering participant thoughts.

In contrast, the other options either may not encourage conversation as effectively or could come across as less inviting. For example, asking about "críticas" could imply a more negative connotation than intended, and simply asking for "dudas" or "preguntas" does not include the opportunity for feedback, potentially limiting the scope of the discussion.