What does “dirty pool” at the end of the second paragraph mean

A．They sensed that something terrible happened, they didn't dare to ask.
B．They were afraid that the writer might lose face if they asked.
C．They'd like to let it be for it was not their business.
D．They tried to calm the writer in this way.

A．feminists have shown little interest in ancient societies
B．reliable information about the ancient world is difficult to acquire
C．ancient societies show the best evidence of women in position of power
D．historians have been primarily interested in the modern period