​Evaluate: 

​$$\sqrt{\left(20 + \sqrt{\left(22 + \sqrt{\left( 2 + \sqrt{\left(40 + \sqrt{(81)}\right)} \right)} \right)}\right)}$$​​

Correct option is C

Given: ​

​$$\sqrt{\left(20 + \sqrt{\left(22 + \sqrt{\left( 2 + \sqrt{\left(40 + \sqrt{(81)}\right)} \right)} \right)}\right)}$$ 

Solution: ​

​$$\sqrt{\left(20 + \sqrt{\left(22 + \sqrt{\left( 2 + \sqrt{\left(40 + \sqrt{(81)}\right)} \right)} \right)}\right)} \\ \ \\ = \sqrt{\left(20 + \sqrt{\left(22 + \sqrt{\left( 2 + \sqrt{\left(40 + 9\right)} \right)} \right)}\right)} \\ \ \\ = \sqrt{\left(20 + \sqrt{\left(22 + \sqrt{\left( 2 + 7 \right)} \right)}\right)} \\ \ \\ = \sqrt{\left(20 + \sqrt{\left(22 +3 \right)}\right)} \\ \ \\ = \sqrt{\left(20 + 5\right)} \\ \ \\ = 5$$​​