To avoid double-counting output in gdp measures, are excluded in gdp. a) government spending b) services such as haircuts c) exports d) raw materials

The correct answer is d). We have that government spending can also give way to products and services, just like private enterprises, thus there is no double-counting there. Services such as haircuts have their own value, which are separate from any other material products. Finally exports are also not counted twice; Raw materials though would be counted twice if we counted them for the GDP since their value is incorporated in the value of the final product. For example, we cannot count towards the GDP the value of rubber production in a country since then, if we counted the value of the tires too, we would count the value of the rubber in the tires twice (one time as rubber/ one time as part of the tire).