The Diagram Below Shows the Activities on the Nodes, and the Table

The diagram below shows the activities on the nodes, and the table shows the normal time and crash time (in days) and cost for each activity.



$$\begin{array} { | c | c | c | c | } \hline \text { Activity } & \text { Normal Time } & \text { Crash Time } & \begin{array} { c } \text { Cost per day } \\\text { to crash }\end{array} \\\hline \text { A } & 6 & 6 & - - - \\\hline \text { B } & 10 & 8 & \$ 100 \\\hline \text { C } & 5 & 4 & \$ 300 \\\hline \text { D } & 4 & 1 & \$ 700 \\\hline \text { E } & 9 & 7 & \$ 500 \\\hline \text { F } & 2 & 1 & \$ 650 \\\hline\end{array}$$
-Determine which activities should be crashed to shorten the project by 1 day.