Please answer the following question: I am testing my students' logic. What is the answer they should choose between "tree" and "paper"? Logic test: Marty writes a letter on a sheet of paper. Later he tries using the pen to draw something on a tree outside. The tip of the pen produces more heat when he uses it against the tree. This is because the _____ offers less resistance. (A) paper (B) tree
A:
tree