Why does Franklin devote a week to each of the virtues?
A:He is afraid he cannot work on more than one virtue at a time.

B:The teachings of Pythagoras and Socrates state that one week is all that is necessary to master a new moral habit

C:He thinks if he can strengthen one virtue through strict attention, he can retain that strength when he works on the rest.

D:He feels that total mastery of one virtue will bring more happiness than incomplete mastery of all virtues.