What observation about baking powder suggests that it is a mixture of substances?

Baking powder is primarily used as a leavening agent in baked goods and products. It is a combination of cornstarch, cream of tartar and baking soda. The main observation that suggests that it is a mixture of substances is that fact that it produces a gas which facilitates the rising of the baked goods.

The correct answer is b, social stratification is needed for a society to exist. marxist theory regarding social stratification is that due to the differing economic capacities among people in society, a natural separation occurs between those that own the means of production and those that sell their labour in the production chain.