The precedence relations and duration (in days) of activities of a project network are given in the table. The total float (in days) of activities $e$ and $f$ , respectively, are
$\begin{array}{|c|c|c|} \hline \textbf{Activity} & \textbf{Predecessors} & \textbf{Duration (days)} \\ \hline a & – & 2 \\ \hline b & – & 4 \\ \hline c & a & 2 \\ \hline d & b & 3 \\ \hline e & c & 2 \\ \hline f & c & 4 \\ \hline g & d,e & 5 \\ \hline \end{array}$
- $0$ and $4$
- $1$ and $4$
- $2$ and $3$
- $3$ and $1$
