$$
\begin{aligned}
&\text { Correct option (d) } 800 \mathrm{w} \\
&\text { Explanation: } \\
&\text { Here, Mass per unit length of water, } \mu=100 \mathrm{~kg} / \mathrm{m} \\
&\text { Velocity of water, } v=2 \mathrm{~m} / \mathrm{s} \\
&\text { Power of the engine, } p=\mu v^{3}=(100 \mathrm{~kg} / \mathrm{m})(2 \mathrm{~m} / \mathrm{s})^{3} \\
&=600 \mathrm{~W}
\end{aligned}
$$