need help with these math questions, explanations would help

Question 1 (3 points) v' Saved Q12D. Assess whether the statement is true or false: The graph shown is not a tree. Question 2 (3 points) Q11. Let T be a spanning tree of graph G. Suppose the spanning tree T has 15 edges. How many vertices must there be in the graph (3? Your Answer: Answer Question 3 (3 points) Q13. Suppose a connected graph, G, has 15 vertices. How many edges must there be in a spanning tree of the graph, (3? Your Answer: Answer Question 4 (3 points) Q15A. Consider the graph with the following vertices and edges: V = {3, b, c, d, e, f} E = {{a, b}, {a, c}. la, d}, la, f]. lb, c}. lb, f}. {c, d}, {(2. f], {d, e}, [d, fl} Which of the following sets of edges represent subgraphs of the graph that are spanning trees? (Select all that apply.) {{a, b}, la, (2}, {a, d}. {a, f}, {d, e}, id, f}} {{a, (3. la. d}, {d. e}. {d, f}} {{a, b}, la, (2}, {a, d}. {a, fl} {{a, b}, {a, c}, {a, d}, {a, f}, {d, e}} {{a, d], {b, C], {(2, d}, id, e}, id, fl} \f