Answer
A path can not go to vertex G from vertex D because vertex D and vertex G are not adjacent. There is no edge which connects vertex D and vertex G.
Therefore, A,C,D,G is not a path.
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 C, and then to vertex D. However, the path can not go to vertex G from vertex D because vertex D and vertex G are not adjacent. There is no edge which connects vertex D and vertex G.
Therefore, A,C,D,G is not a path.