By definition, the Domain of a relation is all the possible input values that can go into the relation.
In this case, given the following ordered pairs of the relation:
[tex]\begin{gathered} A(1,4) \\ G(2,1) \\ P(5,8) \\ S(6,0) \\ Z(7,5) \end{gathered}[/tex]
Having the ordered pairs, you know that, by definition, the domain will be the set of the x-coordinates of the ordered pairs.
Therefore, you can set up that:
[tex]Domain\colon\mleft\lbrace1,2,5,6,7\mright?\rbrace[/tex]
Hence, the answer is:
Last option:
[tex]\lbrace1,2,5,6,7\rbrace[/tex]
