Crowdsourcing in planning involves gathering input from a large, diverse group, often via digital platforms like social media. Option C (use social media to enlist a wide variety of input on a planning project) accurately describes this tool’s primary use, enabling planners to collect ideas and feedback. The APA’sAICP Certification Exam Content Outline(2022), under “Communication and Interaction,” defines crowdsourcing as “a tool that uses social media or digital platforms to gather diverse input for planning projects.” Option A (demographic anomalies) and D (transit demand) are analytical tasks not typically crowdsourced. Option B (crowd gathering locations) misinterprets the term. TheCPC Study Manual(2024) states, “Crowdsourcing helps planners gather wide-ranging input via social media for planning projects,” supporting option C.