Question

which source would be most helpful in researching this question? have helmet laws decreased the number of childhood head injuries? a. a newspaper article titled number of concussions in counties with and without helmet laws b. a medical journal article titled cause and treatment of childhood concussions c. a website featuring an online petition to enact helmet laws in every state d. the biography of a professional cyclist whose career ended after a head injury

Explanation:

The question is about the impact of helmet laws on childhood head - injury numbers. A newspaper article comparing concussion numbers in areas with and without helmet laws directly addresses this research question. Option B focuses on causes and treatments, not the impact of laws. Option C is a petition, not a research - based source. Option D is a biography, not relevant to the impact of helmet laws on childhood head injuries.

Answer:

A. A newspaper article titled "Number of Concussions in Counties With and Without Helmet Laws"