You are a supervisor at a county-level health department, charged with the task of proposing primary prevention interventions to prevent obesity from developing among youth in your community. Which of the following would be interventions that address primary prevention?

A. Conducting training with food service professionals at early childhood education centers on how to design healthy menus

B. Public works projects to develop neighborhood playgrounds

C. Policy requiring food labelling in community grocery vendors

D. A program that provides gently used bikes to low income families

E. All of the above are examples of primary prevention strategies for childhood obesity