The perpendicular distance of the line `px+qy+r=0` from the point (2,-1) is 4 unit , state which of the following conditions is true ?
A. `q+r-2p=4(p^(2)+q^(2))`
B. `q+r-2p=4sqrt(p+q)`
C. `(q+r-2p)^(2)=4(p^(2)+q^(2))`
D. `(2p-q+r)^(2)=16(p^(2)+q^(2))`
