To determine which two organisms are the most closely related based on their amino acid sequences, we can look for similarities in the sequences provided.
- Organism A: Val-Ser-Thr-Val
- Organism B: Leu-Ala-Leu-Ala
- Organism C: Val-Ser-Asp-Met
Comparing the sequences:
- Organism A and Organism C share two amino acids: Val and Ser.
- Organism B has a completely different sequence with no shared amino acids with either A or C.
Given that A and C share more similarities (specifically Val and Ser), they are likely more closely related to each other than to organism B, which has a different sequence.
Thus, the organisms that are most closely related are A & C.
The correct response is:
A & C