Answer:
According to the all-knowing Googs:
"Purgatory, the condition, process, or place of purification or temporary punishment in which, according to medieval Christian and Roman Catholic belief, the souls of those who die in a state of grace are made ready for heaven."
To me, that sounds a heck of a lot like A--"Purgatory is the physical place where the people can purge their worldly belongings to be ready to become monks or nuns."
But if you don't think it's A, and want more information, then so help me I will scour the Googs until I have the answer you seek!