In the figure, it is requested to solve the traveling salesman problem on the line. Which of the following items are correct?

1. The value of the best solution is 56.

2. The set that belongs to the best solution has (E,C) edge.

3. If edge (A,B) was given as selected in the first step and the best solution was sought, the solution would be equal to 63.

4. If the edge (A,B) was given selected in the first step and the branch and bound technique was used as the smallest spanning tree bounding function, the bounding function would have a value of 48.

5. The solution of the traveling salesman problem for all graphs cannot be done in a timely manner.

Explain your answers.