How to solve

Question $2.$ 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. $(4$ points$)$

$\backslash$table$[[$Activity$,$Immediate Predecessors,Time $($week$)],[$A$,-,3],[$B$,$A$,2],[$C$,$A$,4],[$E$,$A$,4],[$F$,$B$,4],[$G$,$C$,$ D$,6],[$H$,$F$,6],[$I$,$E$,$ G$,$ H$,3]]$