Two electric charges $12 \mu C$ and $-6 \mu C$ are placed $20\;cm$ apart in air, there will be a point $P$ at which electric potential is zero on the line joining these two charges and out side excluding the region between them. The distance of $P$ from $-6 \mu C$ charge is :

Question

( A ) 0.10 m
( B ) 0.15 m
( C ) 0.20 m
( D ) 0.25 m