Which of these statements about Roman baths is true?

Which of these statements about Roman baths is true?
A、The water in Roman baths was changed daily to maintain hygiene.
B、Public bathing was free for all citizens.
C、Baths were always segregated by gender.
D、Hygiene was not a concern in Roman baths as people bathed with their clothes on.
【正确答案】：B
【题目解析】：Public bathing was free for all citizens. (Although this varied over time and location, public baths were often subsidized or free for citizens.)