A large tank with a nozzle attached contains three immiscible inviscid fluids as shown. Assuming that the changes in h1, h2 and h3 are negligible, the instantaneous discharge velocity is:

• A. \(\sqrt {2g{h_3}\left( {1 + \frac{{{\rho _1}{h_1}}}{{{\rho _3}{h_3}}} + \frac{{{\rho _2}{h_2}}}{{{\rho _3}{h_3}}}} \right)}\)
• B. \(\sqrt {2g\left( {{h_1} + {h_2} + {h_3}} \right)}\)
• C. \(\sqrt {2g\left( {\frac{{{\rho _1}{h_1} + {\rho _2}{h_2} + {\rho _3}{h_3}}}{{{\rho _1} + {\rho _2} + {\rho _3}}}} \right)}\)
• D. \(\;\sqrt {2g\left( {\frac{{{\rho _1}{h_2}{h_3} + {\rho _2}{h_3}{h_1} + {\rho _3}{h_1}{h_2}}}{{{\rho _1}{h_1} + {\rho _2}{h_2} + {\rho _3}{h_3}}}} \right)} \)