Step 1: Use the definition of the plotted quantity.
By the problem statement, the plotted ordinate is
\[
\text{Electricity cost per sq. ft.} \;=\; \frac{\text{Total electricity cost (in ₹)}}{\text{Output (in sq. ft.)}}.
\]
Therefore, for each output level \(Q\), we compute
\[
e(Q) \;=\; \frac{\text{Electricity cost at }Q}{Q}.
\]
Step 2: Compute \(e(Q)\) for each given output.
From the table (costs read from the question data), the electricity cost values (in ₹) lead to the following per-unit costs:
\[
\begin{array}{c|c|c}
\text{Output }Q\;(\text{sq. ft.}) & \text{Electricity cost }(₹) & e(Q)=\frac{\text{cost}}{Q}\;(₹/\text{sq. ft.})
\hline
25{,}000 & 3800 & 0.15
50{,}000 & 5700 & 0.11
75{,}000 & 8550 & 0.11
100{,}000 & 12{,}825 & 0.13
125{,}000 & 19{,}237.5 & 0.15
150{,}000 & 28{,}856.25 & 0.19
175{,}000 & 38{,}586.5 & 0.22
200{,}000 & 48{,}856.75 & 0.24
\end{array}
\]
Step 3: Infer the qualitative shape.
Reading the sequence of per-unit costs:
\[
0.15 \;\Rightarrow\; 0.11 \;\Rightarrow\; 0.11 \;\Rightarrow\; 0.13 \;\Rightarrow\; 0.15 \;\Rightarrow\; 0.19 \;\Rightarrow\; 0.22 \;\Rightarrow\; 0.24.
\]
Thus, the curve \emph{first decreases} from \(25{,}000\) to \(50{,}000\)–\(75{,}000\) sq. ft. (down to about \(0.11\)), and then \emph{increases steadily} up to \(200{,}000\) sq. ft. (reaching about \(0.24\)).
The only candidate whose shape matches “dip to \(\approx 0.11\) early, then smooth rise to \(\approx 0.24\)” is
Option B.
\[
\boxed{\text{Therefore, the correct diagram is }
B.}
\]