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Catalytic converters on motor vehicle exhausts are a way of trying to reduce the carbon monoxide and nitrogen oxide emissions. Which of the following are correct?

I. The catalyst used is either platinum or a combination of platinum and rhodium.
II. The platinum catalyses the reaction of cO and NO to form CO2 and N2 gas
III. The rhodium catalyses the reaction of unburnt hydrocarbon and O2 to produce CO2 and H20 vapor
IV. The reduction of NO to N2 must proceed more quickly than the oxidation of CO to CO2 or else all the CO will be oxidized to carbon dioxide before it can be used to reduce the nitric oxide
V. Motor vehicles can only use catalytic converters if they use unleaded petrol since the lead in petrol renders the catalyst inactive.

1. I, II, III

2. I, IV, V

3. I, III, IV

4. III, IV, V