The following table of probabilistic time estimates $($in weeks$)$ and activity predecessors are provided for a project.

Activity

optimistic

time

most likely

time

pessimistic

time

Activity Predecessor

A

$3$

$5$

$7$

$--$

B

$4$

$8$

$10$

A

C

$2$

$3$

$5$

A

D

$6$

$9$

$12$

B$,$ C

E

$5$

$9$

$15$

D

Table $1$

Reference: Ref $1$

Using Table $1,$ the variance for activity E is

A$.2\mathrm{.}582.$

B$.2\mathrm{.}778.$

C$.1\mathrm{.}667.$

D$.1\mathrm{.}291.$