Two forces having magnitude A and $$\dfrac{A}{2}$$ are perpendicular to each other. The magnitude of their resultant is:

A

$$\dfrac{\sqrt{5}A}{4}$$

B

$$\dfrac{\sqrt{5}A}{2}$$

C

$$\dfrac{5A}{2}$$

D

$$\dfrac{\sqrt{5}A^2}{2}$$