1.Val-Lys + Glu-Met-Ser + Trp-Arg-Ala
2. Val-Lys-Glu-Met-Ser-Trp + Arg-Ala
3. Val-Lys-Glu-Met + Ser-Trp-Arg-Ala
4.Val-Lys-Glu + Met-Ser-Trp-Arg-Ala
Answer:3