A professor at a university finds a way to reduce the costs of producing automobile glass. The method is very easy for anyone to copy. A company develops a substance which prevents eyeglasses from smudging. It receives a patent on the formula. Which of these are common technological knowledge?
a.) the method to reduce costs of producing automobile glass, and the formula for the substance that prevents smudging
b) the method to reduce costs of producing automobile glass, but not the formula for the substance that prevents smudging
c) the formula for the substance that prevents smudging, but not the method to reduce costs of producing automobile glass
d) neither the method to reduce costs of producing automobile glass nor the formula for the substance that prevents smudging

As provided, the professor develops a way which shall reduce the cost of producing the automobile glass, which apparently is very easy for anyone to copy and use.

Whereas, when a company develops the formula which creates a substance that prevents the automobile glass from getting smudged is again a technological knowledge although not that common.

Since the first one is apparently easy and other is patented which means both are common else not so common idea will not need patent as people would not be able to create such formula.