Candidates Joy, Ned, and Harvey are on a ballot to be the county treasurer.
The table shows preference orders for six people's votes (J = Joy, N = Ned, H = Harvey). How many unique preference orders are represented in the table?
Voter 1
Voter 2
Voter 3
Voter 4
Voter 5
Voter 6
1st
J
N
J
J
H
N
2nd
N
J
N
N
N
J
3rd
H
H
H
H
J
H
1.
three
2.
six
3.
five
4.
four