A school boy lying on the ground \(30 \mathrm{~m}\) away from the foot of a water tank observes that the angle of elevation of the top of the tank is \(60^{\circ}\). Calculate the height of the water \(\operatorname{tank}\).
A. \(60 \mathrm{~m}\) B. \(30 \sqrt{3} \mathrm{~m}\) C. \(20 \sqrt{3} \mathrm{~m}\) D. \(10 \sqrt{3} \mathrm{~m}\)