This MST-KRuskal algorithm is on page 631 of an algorithms book (CLRS):

Here is the question that I need help with.

MST KRUSKAL (G, w) 1 A 2 for each vertex v E G.V 3 MAKE-SET (v) 4 sort the edges of G.E into nondecreasing order by weight w 5 for each edge (u, v) e G.E, taken in decreasing order by weight 6 if FIND-SET (a) FIND-SET (v) A U (u, v) UNION(u, v) 9 return A