Web Studio to capture Query parameters from social media link is the correct answer. This option allows you to create landing pages or microsites using Marketing Cloud tools and data that can capture information from users who visit your pages from social channels, such as Facebook or Twitter. You can use query parameters in your social media link to pass information such as user ID, name, email address, etc., and then use AMPscript or SSJS code in your Web Studio page to retrieve and store that information in a data extension or list for future mailing. Use Journey Builder to build an audience using Ad Studio is not a valid option, as this option only allows you to create audiences based on existing contacts in Marketing Cloud or Salesforce CRM, not new users from social channels. Use an interactive form from Email Studio to collect this information is not a valid option either, as this option only allows you to collect information from users who already receive your emails, not new users from social channels. You can learn more about this in the [Web Studio Basics] module on Trailhead.