Given,

$\sqrt{888888}1.486=?$

It can also be approximated as

$$\begin{gathered} = \sqrt{900000}÷1.5=? \\ = \sqrt{90\times 100\times 100}\times 1.5 \end{gathered}$$

= 9.5×10×10×1.5

= 950×1.5

= 1425 ≈ 1400

Hence, Option D is correct.