You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

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
B