give a try at
(From x in YourArrVa
Group x by k1=x(0), k2=x(1),k3=x(2) into grp=Group
Select r=grp.First()).toArray
give a try at
(From x in YourArrVa
Group x by k1=x(0), k2=x(1),k3=x(2) into grp=Group
Select r=grp.First()).toArray