Consider the Transportation Problem and Its Initial Solution in the Table

Multiple Choice

Consider the transportation problem and its initial solution in the table below. What is the improvement index for the empty cell Source 1 - Destination 3?
$\begin{array}{|l|r|r|r|r|r|}\hline \text { COSTS } & \text { Dest. 1 } & \text { Dest. 2 } & \text { Dest. 3 } & \text { Dest. 4 } & \text { Supply } \\\hline\text { Source 1 } & 12 & 18 & 9 & 11 & 45 \\\hline\text { Source 2 } & 19 & 7 & 30 & 15 & 145 \\\hline\text { Source 3 } & 8 & 10 & 14 & 16 & 50 \\\hline \text { Demand } & 80 & 30 & 70 & 60 & 240/240 \\\hline & & & & & \\\hline \text { Shipments } & \text { Dest. 1 } & \text { Dest. 2 } & \text { Dest. 3 } & \text { Dest. 4 } & \text { Row Total } \\\text { Source 1 } & 45 & 0 & 0 & 0 & 45 \\\text { Source 2 } & 35 & 30 & 70 & 10 & 145 \\\text { Source 3 } & 0 & 0 & 0 & 50 & 50 \\\text { Col. Total } & 80 & 30 & 70 & 60 & 240/240 \\\hline\end{array}$

A) 0
B) -14
C) -23
D) -70
E) 115