Quiz: Adjacency Matrix vs List

You have a graph with $10{,}000$ vertices and $15{,}000$ edges. Which representation uses less memory, and why?

1. A.Adjacency matrix, because it avoids pointer overhead
2. B.Adjacency matrix, because it stores each edge once
3. C.Adjacency list, because it only stores $10{,}000$ entries
4. D.Adjacency list, because it stores $O(V + E)$ instead of $O(V^2)$