Answer: Option B
Explanation: In economics, derived demand is demand for a production factor or intermediate good arising from the demand for some other intermediate or final good.
In general, a company's demand for, say, a production factor depends on consumer demand for the company's product.The commodities in such a demand structure are indirectly related to each other.
Hence from the above we can conclude that the correct option is B as the demand for the authors guide is directly linked to other product that is college textbooks.
