Let, D = be a directed graph or digraph,then D’ = is a subgraph if ___________

• A. A’ ⊂ A and R’ = R ∩ (A’ x A’)
• B. A’ ⊂ A and R ⊂ R’ ∩ (A’ x A’)
• C. R’ = R ∩ (A’ x A’)
• D. A’ ⊆ A and R ⊆ R’ ∩ (A’ x A’)