A Project Consists of Four Activities with Information as Shown

Multiple Choice

A project consists of four activities with information as shown in the table.What is the overall standard deviation of the project's duration? $\begin{array}{|l|l|l|l|}\hline&&&\text { Standard }\\ \text { Activity } & \text { Predecessor } & \text { Length } & \begin{array}{l}\text { Deviation }\end{array} \\\hline \text { A } & - & 10 & 2 \\\hline \text { B } & \text { A } & 12 & 3 \\\hline \text { C } & \text { A } & 16 & 2 \\\hline \text { D } & \text {B,C} & 14 & 3\\\hline \end{array}$

A) 6.2
B) 4.1
C) 2.8
D) 5.1