Task: Question Answering
Input (English): A Raleigh man turned on his kitchen faucet and filled a glass with water. When he looked at the water, he thought that it might not be safe to drink, so he called the water company to find out. What factor did the man use to evaluate the safety of the water?  
 (A) pH (B) turbidity (C) nitrate concentration (D) phosphate concentration
Output (English): B