Given the following information for an AOA network:

Immediate

$\backslash$table$[[$Activity$,$Duration $($days$),$Predecessor$($s$)],[$A$,4,$None$],[$B$,2,$A$],[$C$,7,$None$],[$D$,4,$A$],[$E$,5,$B$,$C$,$D$]]$

How many dummy arc$($s$)$ is $($are$)$ there in this AOA network?

Keep your own AOA graph.

Select one:

a$.$ four dummy arcs

b$.$ one dummy arc

c$.$ no dummy arc

d$.$ three dummy arcs

e$.$ two dummy arcs