The surface energy of a liquid drop is E. It is sprayed into 1000 equal droplets. Then their surface energy is

A droplet's surface area directly relates to its surface energy. Let each droplet to have a radius of r after spraying 1000 times.

$$\begin{gathered} \frac{4}{3}{\mathrm{\pi R}}^3=1000\left(\frac{4}{3}{\mathrm{\pi r}}^3\right) \\ \mathrm{r}=\frac{\mathrm{R}}{10} \end{gathered}$$

The surface area of 1000 droplets is as a result:

$1000\times \left(4\pi r^3\right)=n\left(4{\mathrm{\pi R}}^3\right)$

where n is the multiplicity of the initial surface area.
Surface area will therefore become 

$\frac{1000\left(4{\mathrm{\pi r}}^2\right)}{4{\mathrm{\pi R}}^2}=\mathrm{n} \mathrm{times}=10\mathrm{times}$

$\mathrm{E}\propto \mathrm{A}$

$\mathrm{Hence}, \mathrm{E} \text{'}=10\mathrm{E}$

Hence the correct answer is 10E.