Which city has the highest number of students failing the entrance exam?

Answer: Option D

Number of failures from different cities:
$$\begin{array}{rl}& \text{A}\to 1.25\times 100000\times \frac{3}{10}\\ & =37500\\ & \text{B}\to 3.14\times 100000\times \frac{3}{8}\\ & =\frac{314000\times 3}{8}\\ & =117750\\ & \text{C}\to 1.08\times 100000\times \frac{5}{9}\\ & =108000\times \frac{5}{9}\\ & =60000\\ & \text{D}\to 2.27\times 100000\times \frac{3}{4}\\ & =227000\times \frac{3}{4}\\ & =170250\\ & \text{E}\to 1.85\times 100000\times \frac{2}{5}\\ & =185000\times \frac{2}{5}\\ & =74000\\ & \text{F}\to 2.73\times 100000\times \frac{5}{12}\\ & =273000\times \frac{5}{12}\\ & =113750\end{array}$$
So,
The maximum number failures are from city D.