Water is flowing continuously from a tap having an internal diameter $8 \times 10^{-3}$m. The water velocity as it leaves the tap is $0.4\; ms^{-1}$. The diameter of the water stream at a distance $2 \times 10^{-1}$ m below the lap is close to :

Question

( A ) $3.6 \times 10^{-3}$ m
( B ) $7.5 \times 10^{-3}$ m
( C ) $5.0 \times 10^{-3}$ m
( D ) $9.6 \times 10^{-3}$ m