A project is represented by the activity durations (estimated at 90% likelihood of completion) and precedence requirements shown in the table. What is the length of the project buffer if this project is managed using critical chain methodology?

Activity	Predecessor	Length	Activity	Predecessor	Length
M	--	8	R	--	12
N	--	8	S	P	14
P	M	12	T	R, Q	7
Q	N	10	V	S, T	11

Group of answer choices

13.5

22.5

11.25

9.0