Which of the following statements are TRUE, where |E| represents the number of edges. 

(A). In case of a directed graph, the sum of lengths of all the adjacency list is E 

(B). For an undirected graph, the sum of the lengths of all the adjacency list is 2|E| 

(C). For a dense graph, adjacency matrix representation is preferable 

(D). The memory requirement of the adjacency matrix of a graph is dependent on the number of edges 

Choose the correct answer from the options given below:

1. (A), (B) and (D) only 

2. (A), (B) and (C) only 

3. (A), (B), (C) and (D) 

4. (B), (C) and (D) only