Choose the best summary of the passage.
A. No two concussions are alike. Some people may recover easily from concussion, while others may take weeks or months. In any case, receiving a second concussion too soon may mean a lengthy recovery.
B. When baseball players receive concussions, some take a long time to recover. Some may try to return to play too soon and receive a second concussion that ends their careers.
C. Although most athletes shrug off concussions, they would be wise to take them seriously. Multiple concussions can cause serious harm to the brain, which is rattled around in the skull with each injury.
D. Recovery from concussion is possible, but it is not always a good idea to return to play too soon. Some head injuries are called concussions but do not really qualify as such.