Answer: Yes, this relation is function.
Step-by-step explanation:
A relation is called function if each input has unique output.
It is given that, Juan has blood type A, Lilly has blood type AB, and Aaron has blood type O.
Juan is related to blood type A.
Lilly is related to blood type AB.
Aaron is related to blood type O.
Here, each input has unique output because here each person has unique blood group.
Therefore, this relation is a function.