If $$A(p,q+r)$$, $$B(q,r+p)$$ and $$C(r,p+q)$$ are points then area of triangle $$ABC$$

A

$$p^2+q^2+r^2$$

B

$$(p+q+r)^2$$

C

$$\frac12(pq+qr+rp)$$

D

zero