Activity

A

$--$

$3$

B

A

$2$

C

A

$4$

D

A

$4$

E

B

$6$

F

$6$

G

$2$

H

D

$3$

I

$3$

The R&D department is planning to bid on a large project for the development of a new communications system for commercial planes. The accompanying table shows the activities, times, and sequences required:

Which of the following are steps that, if shortened, would not shorten the total duration of the activity

F

A

B

I