Complex sentence: Greene challenged Mel Lastman for Mayor of North York in 1985, arguing that Lastman had "den (ied) North York residents the right to participate in planning their neighborhoods", and promising a more open government.
Split into simpler sentences: Greene challenged Mel Lastman for Mayor of North York in 1985. She argued that Lastman "den (ied) North York residents the right to participate in planning their neighborhoods", and promised a more open government.