The radii of two concentric circles are x cm and 26 cm. P and S are the points on larger circle and Q and R are points smaller circle. If PQRS is a straight line and QR = 40 cm and PS = 45 cm, then what is the value of x? (x < 26 cm)

A

$$11\surd{5}$$ cm

B

$$10\surd{5}$$ cm

C

$$12\surd{5}$$ cm

D

$$9\surd{5}$$ cm