Length and breadth of a rectangle are 8 cm and 6 cm respectively. The rectangle is cut on its four vertices such that the resulting figure is a regular octagon. What is the side (in cm) of the octagon?

A

$$3(\surd11)-7$$

B

$$5(\surd13)-8$$

C

$$4(\surd7)-11$$

D

$$6(\surd11)-9$$