d
Thrust $=$ Rate of charge of linear momentum
Thrust $=\mathrm{mv}$ where $\mathrm{m}$ is mass striking per sec.
$=\rho a v \times v \Rightarrow \quad$ Thrust $=\rho a v^{2}$
Energy lost for second $=\frac{1}{2} m v^{2}=\frac{1}{2} \rho a v . v^{2}=\frac{1}{2} \rho a v^{3}$
so option $(\mathrm{B}, \mathrm{C})$ are correct.