The correct answer is D. Specific knowledge is excludable, while general knowledge is not excludable.
Explanation:
General knowledge refers to information, facts, etc. that are basic, and due to this, they are known by most of the people. Indeed, general knowledge is obtained through basic education, interaction with others and exposition to media. Moreover, general knowledge covers multiple areas. On the other hand, specific knowledge focuses on specific areas and covers complex facts, information, etc. Also, in most cases, specific knowledge can only be acquired through formal training or education.
Besides, in terms of excludability (quality of a service or product that needs to be paid to be acquired), specific knowledge is mainly excludable because people who do not pay for formal training cannot obtain it. On the opposite, general knowledge is not excludable as this can be obtained for free, and therefore it is not possible to control this (Option D).
