Answer
A,B,C,C,D,F,G,H,I
Work Step by Step
A path is a sequence of adjacent vertices. Two vertices are adjacent if there is an edge which connects the two vertices.
From vertex A, a path can go to vertex B, then to vertex C, then through the loop back to vertex C, then to vertex D, then to vertex F, then to vertex G, then to vertex H, and then to vertex I. This path is A,B,C,C,D,F,G,H,I