If from the point $P(a,b,c)$ perpendiculars $PA$ and $PB$ are drawn to $yz$ and $zx$ planes respectively then the vector equation of the plane $OAB$ is ?

Question

$(a)\: \overrightarrow r.(a\hat i+b\hat j+c\hat k)=0 \:\qquad (b) \: \overrightarrow r.(\large\frac{\hat i}{a}+\frac{\hat j}{b}-\frac{\hat k}{c})=0$$ (c)\:\:\overrightarrow r.(a\hat i+b\hat j-c\hat k)=0\:\qquad (d)\:\:\overrightarrow r.(\large\frac{\hat i}{a}+\frac{\hat j}{b}+\frac{\hat k}{c})=0$