What new feature did Semrush launch to help marketers create social media content in a zilch?

Social Content AI is the correct answer because Semrush launched this specific feature to assist marketers in generating social media content quickly. It leverages AI to help create captions, hashtags, and post ideas, streamlining the content creation process. Caption Builder is incorrect because while Semrush might have tools for captions, "Caption Builder" is not the designated name for this new, comprehensive AI-powered social media content generation feature. Design Magic AI is incorrect because this name suggests a focus on visual design, whereas the new Semrush feature is primarily about generating textual content and ideas for social media. Calendar Builder is incorrect because this refers to a tool for scheduling and organizing content, not for generating the content itself.