ReCAPTCHA ensures you only collect user responses, not bot ones, and can be set up for all item types.
About reCAPTCHA
Google reCAPTCHA helps filter out bots by presenting simple tests that are easy for humans but difficult for automated programs. Users may be asked to solve puzzles or identify objects in images. Once verified, they can participate in the poll, quiz or form/survey. Invisible reCAPTCHA works in the background, detecting bots without user interaction.
How to set up reCAPTCHA?
Open your item and scroll down to the Settings section.
Select the Enable reCAPTCHA checkbox:
Make sure to publish the changes.
You can read more about reCAPTCHA here.