Step-by-step Solution:

Graphs can be represented using different representations depending on the context and nature of the problem. The three common ways to represent a graph are:\[\] 1. Adjacency List: This is a collection of lists (or arrays), where each index represents a vertex and the list at that index contains all the vertices adjacent to it. It is efficient for sparse graphs (fewer edges).\[\] 2. Adjacency Matrix: This is a 2D matrix that represents the presence of edges between nodes. A value of 1 (or the edge's weight) indicates a connection between two nodes, while 0 indicates no connection. It is efficient for dense graphs.\[\] 3. Incidence Matrix: This is a matrix where rows represent edges, columns represent vertices, and the entries show whether a given edge is incident to a vertex. It is less commonly used but can be useful in certain graph algorithms.\[\] \[\] Correct Answer: (d)