In Act 4 of "The Crucible," Parris suggests that Abigail and Mercy ran away because they feared the consequences of their actions, particularly in light of the rebellion in Andover. Therefore, the correct answer is:
B. The rebellion in Andover would motivate the people of Salem to turn against the girls.
Parris believes that this unrest might shift the town's sentiments against Abigail and the other girls who have been causing chaos in Salem.