Which of these best characterizes what multidimensional scaling (MDS) is used for?
1) To find the shortest route among available flight connections from one airport to another
2) To layout nodes in a complete graph (every node connected to every other node by an edge) according to desired edge lengths
3) To find the directions in a high dimensional dataset where the data varies the most
4) To layout nodes in a planar graph so that the edges do not cross