Scientists can determine relatedness among organisms by comparing partial amino acid sequences. The table shows four partial amino acid sequences from four organisms.

Which organism is the LEAST related to the other three organisms?

Organism 1 SER LEU VAL GLU
Organism 2 LEU SER ASN VAL
Organism 3 ALA LEU SER GLU
Organism 4 THR LEU SER GLU

Organism 2 is the LEAST related to the other three organisms.