A triangular park is enclosed on two sides by a fence and on the third side by a straight river bank. The two sides having fence are of same length $$x$$. The maximum area enclosed by the park is

A

$$\dfrac{3}{2}x^2$$

B

$$\sqrt{\dfrac{x^3}{8}}$$

C

$$\dfrac{1}{2}x^2$$

D

$$\pi x^2$$