A project is made of three activities. Activity A is lasting for 5 weeks, activity B is lasting for 6 weeks, activity C is lasting for 7 weeks, the taxis is A-B-C. While, it will take 1 week for resource distribution of activity B, and activity C will start in one week after the beginning of activity B. What is the shortest time limit for this project?
A、12 weeks
B、13 weeks
C、14 weeks
D、16 weeks