单项选择题
A.k+1B.kC.k-1D.2k
A.δ(G)≤λ(G)≤k(G)B.δ(G)≤k(G)≤λ(G)C.k(G)≤λ(G)≤δ(G)D.λ(G)≤k(G)≤δ(G)
A.nB.n-1C.1D.n+1