(40 points) A student is writing a research report for her science class about ideas for reducing head injuries in football. The student must use sources that are credible, trustworthy, and relevant for the topic.

Which of these is MOST LIKELY a credible and trustworthy source that is relevant for the topic?
A.
an article in a sports medicine journal about studies that have been done on practices that have lowered head injury rates
B.
a blog written by a football player who is not in favor of making changes to the rules or equipment of the sport
C.
an entry in an online encyclopedia about the history of football and how head protection has changed over time
D.
a petition signed by 15,000 football players who want steps to be taken to reduce the number of head injuries in football