What is a CAPTCHA used for in form submissions?

A CAPTCHA is primarily designed to determine if a user is human or a bot. This mechanism is crucial in preventing automated software from submitting forms, which can lead to spam and malicious activities. By presenting challenges that are simple for humans to solve but difficult for bots, CAPTCHAs help ensure that form submissions are genuine and from legitimate users.

The effectiveness of CAPTCHAs in distinguishing between human and bot activity is essential for maintaining the integrity of data collected through forms. This is particularly important in marketing platforms like Marketo Engage, where accurate data is vital for targeting and analytics.

In contrast, the other options do not align with the primary function of a CAPTCHA. Collecting user feedback, assessing form usability, and tracking user interactions with the form are valuable activities, but they do not involve the security aspect that CAPTCHAs provide in distinguishing between human users and automated scripts.