In an experiment with potentiometer, the balancing length is 250 cm for a cell. When the cell is shunted by a resistance of $$7.5\ \Omega$$, balancing point is shifted by 25 cm. If the cell is shunted by a resistance of $$20\ \Omega$$, the balancing length will be nearly

A

240 cm

B

236 cm

C

232 cm

D

230 cm