The H.C.F. of 910, 1225, 1835 and 2140 is:

Answer: Option C

$$\begin{array}{rl}& \text{Required}\text{H}\text{.C}\text{.F}\text{.}\\ & =\frac{\text{H}\text{.C}\text{.F}\text{.}\text{of}9,12,18,21}{\text{L}\text{.C}\text{.M}\text{.}\text{of}10,25,35,40}\\ & =\frac{3}{1400}\end{array}$$