_/20
This Is A Surd, In Order To Solve A Surd Question You Need To Look For The Numbers One Which Is "Rational" And The Other Which Is "Irrational"
Rational Number: This Are Number That The Root Give A Whole Number e.g _/4, _/16 etc
Irrational Number Is Opposite Of Rational
_/20
= _/4*5
= _/4 * _/5
= 2*_/5
=2_/5
OA Is Correct