A project has four major activities. 

Activity A precedes activity B, activity C precedes activity D. 

3-point estimates for activities are

A(9.5, 19, 28.5 ), 

B( 4.5, 9, 13.5 ), 

C( 2, 2, 2 ), 

D( 3, 3, 3 ) weeks. 

What probability would you assign to a project duration of more than 28 weeks? 

Select one: 

a. 0.3388 

b. 1 

c. 0.5 

d. 0.8645