A. 2.
A radical is an expression which implies the use of a root.
There are three components of a radical expression:
(i) The root "√".
(ii) The radicand √"a".
(iii) The degree or index of the radical [tex]\sqrt["n"]{a}[/tex], when index of the radical is not shown then it understood to be a index of 2.
The index is the number used to indicate the degree of the root.
For the example [tex]\sqrt{10}[/tex], 10 is the radican and the index is not shown so it understood is 2.
