Use the Data to Calculate the Schedule Performance Index for the Project

Use the data to calculate the schedule performance index for the project for the end of week 20.The earned value as of the end of week 20 is indicated in the table.All amounts are in thousands of dollars. Duration (weeks)
$$\begin{array} { | l | l | l | l | l | l | l | } \hline & 5 & 10 & 15 & 20 & 25 & \%\mathrm { Cormp } \\\hline \text { Conceptual desiern } & 10 & 6 & & & & 100 \% \\\hline \text { Craphics desigrl } & & 12 & 6 & 4 & & 100 \% \\\hline \text { Copyright } & & & 4 & 5 & 6 & 60 \% \\\hline \text { Barmples } & & & 4 & 2 & & 100 \% \\\hline \text { Toolirg } & & & 6 & 9 & 4 & 50 \% \\\hline \text { Production } & & & 2 & 6 & 14 & 20 \% \\\hline \text { Total } & 10 & 18 & 22 & 26 & 24 & \\\hline \text { Currulative } & 10 & 28 & 50 & 76 & 100 & \\\hline\end{array}$$

A) 1.14
B) 0.88
C) 0.94
D) 0.81