The cars at dealership come with a choice of the following options: air conditioning, a cassette deck, leather seats, power windows, a sunroof and tinted glass. None of the cars has any other optional equipment. The following conditions apply:
If a car has leather seats, it also has a cassette deck. If car has a cassette deck, it also has power windows; If a car has power windows, it also has cassette deck.
Cars with tinted glass have a sunroof, but no air-conditioning. Cars that have air-conditioning have at most two other options.
If a car has power windows and a sunroof, how many different sets of options at most can the car have?