A project is represented by the following diagram:

A project diagram with activities represented by circles and arrows indicating the sequence of these activities. There are nine nodes in total, labeled $$a$,4,$b$,5,$c$,3,$d$,5,$e$,7,$f$,2,$g$,6,$h$,1,$ and $$i$,3.$ The arrows indicate the direction of flow between these activities: from $$a$$ to $$b$$ and $$c$,$ from $$b$$ to $$e$,$ from $$c$$ to $$g$,$ from $$d$$ to $$h$,$ from $$e$$ to $$h$,$ from $$f$$ to $$g$,$ and from $$g$$ and $$h$$ to $$i$.$

The expected duration of this project is

Multiple Choice

$12.$

$17.$

$20.$

$36.$

$77.$