Given,

$\sqrt{\text{769}}_3\times \sqrt{\text{478}}\text{ =?}$

It can be approximated as

$\sqrt{\text{769}}_3\times \sqrt{\text{478}}\text{ =?}$

= 9×22

= 198 ≈ 200

$\left[\because \sqrt{729}=9, \sqrt{484}=22\right]$

[ here we decrease the value of 769 to 729]

Hence, Option D is correct.