Context: Read the description of a trait.
Tom has a scar on his left knee.
What information supports the conclusion that Tom acquired this trait?
A. Tom's scar was caused by an accident. He cut his leg when he fell off his skateboard.
B. Tom's scar is on his left knee. His mother also has a scar on her left knee.
C. Tom's brother has scars on both of his knees.
Select the correct answer from the provided options and reply with the letter associated with it.

A