Answer
PC CC FRSC OOnt FRS are the post-nominal letters for John Polanyi's titles in Canada. PC stands for Privy Councillor, CC for Companion of the Order of Canada, FRSC for Fellow of the Royal Society of Canada, OOnt for Order of Ontario, and FRS for Fellow of the Royal Society. These titles recognize Polanyi's significant contributions to science, particularly in the field of chemical kinetics, and his service to Canada.