Task: Question Answering
Input (English): Kendall studied the ways in which human body systems work together. He compared the respiratory and circulatory systems. In which way are these two systems similar to each other?  
 (A) They both bring oxygen to the body. (B) They both send messages to the body. (C) They both digest nutrients for the body. (D) They both pump blood through the body.
Output (English): A