How do I eliminate the cells in COL A whose contents do NOT match the
contents of the cells in COL C. For the matching cells, I also need
to know the contents of the cells in COL B.

A B C
101170041-1 101180013-7
101170042-2 Y 101200001-7
101170043-3 101200004-0
101180013-7 A 101200005-1
101180014-8 Y 101200006-2
101180015-9 Y 101200007-3
101180016-0 C 101200008-4
101180017-1 C 101200009-5
101180018-2 C
101180020-3 Y
101180021-4 C
101180033-5 C
101190029-3 Y
101190034-7 Y
101190048-0
101190060-0 Y
101190064-4
101200001-7 Y
101200004-0 Y
101200005-1 Y
101200006-2 Y
101200007-3 Y
101200008-4 A
101200009-5 Y
101200010-5 Y
101200011-6 Y
101200012-7 Y
101210001-8 C
101210003-0 A
101210004-1 A
101210010-6 A
101210011-7 A