On putting a capillary tube in a pot filled with water, the level of water rises up to a height of $4 \mathrm{~cm}$ in the tube. If a tube of half the diameter is used, the water will rise to the height of nearly
(A) $2 \mathrm{~cm}$
(B) $5 \mathrm{~cm}$
(C) $8 \mathrm{~cm}$
(D) $11 \mathrm{~cm}$