A design charrette is a collaborative, hands-on workshop where community members work with planners to provide input on a project, such as a park design, ensuring their ideas shape the outcome. Option A (design charrette) is most likely to generate useful input, as it directly involves residents in the design process. The APA’sAICP Certification Exam Content Outline(2022), under “Communication and Interaction,” describes design charrettes as “a participatory method to gather detailed community input on design projects like parks.” Option B (information campaign) informs but doesn’t collect input. Option C (park cleanup) fosters engagement but not design input. Option D (research trends) is a planner-led activity, not community-driven. TheCPC Study Manual(2024) states, “Design charrettes are highly effective for generating useful community input on park design by involving residents directly,” supporting option A.