Answer: Option C
$$\eqalign{
& {\text{Speed}} \cr
& {\text{ = }}\left( {60 \times \frac{5}{{18}}} \right){\text{m/sec}} \cr
& {\text{ = }}\frac{{50}}{3}{\text{m/sec}} \cr
& {\text{Time = 27 sec}}{\text{.}} \cr
& {\text{Let the length of the train be }}x{\text{ metres}}{\text{.}} \cr
& {\text{Then,}}\frac{{x + 200}}{{27}}{\text{ = }}\frac{{50}}{3}{\text{ }} \cr
& \Leftrightarrow x + 200 = \left( {\frac{{50}}{3} \times 27} \right) = 450 \cr
& \Leftrightarrow x = 450 - 200 = 250{\text{ metres}} \cr} $$