The pursuit of self interst:

a) is highly detrimental to the market system
b) means the same as "selfishness"
c) is reflected in the behavior of firms, but not in the behavior of consumers
d) gives direction to the market system

The answer to this question requires understanding the concept of self-interest and its relation to the market system. By explaining each option, we can determine the correct answer.

a) "is highly detrimental to the market system": To evaluate this option, we need to understand the impact of self-interest on the market system. Self-interest refers to individuals acting in ways that benefit themselves. In a market system, self-interest motivates individuals to pursue their own economic goals, which can lead to productive and efficient outcomes. Therefore, option a) is not correct, as self-interest is not detrimental to the market system.

b) "means the same as 'selfishness'": To determine if this statement is true, we need to differentiate between self-interest and selfishness. Self-interest is about individuals acting to achieve their own goals, while selfishness implies a disregard for others. While self-interest can be pursued without selfishness, they are not necessarily the same. Hence, option b) is not correct.

c) "is reflected in the behavior of firms, but not in the behavior of consumers": This statement suggests that self-interest applies only to firms and not to consumers. However, self-interest applies to both firms and consumers. Firms aim to maximize profits, which represents self-interest, while consumers seek to maximize their satisfaction or utility. Thus, option c) is not correct.

d) "gives direction to the market system": This option acknowledges that self-interest plays a significant role in shaping the market system. Self-interest guides individuals' decisions, such as what goods or services to produce, how much to produce, and at what price to sell. These decisions collectively determine the direction of the market system. Therefore, option d) is correct.

In conclusion, the correct answer is d) "gives direction to the market system." Self-interest influences and guides the decisions and actions of individuals, playing a pivotal role in shaping the market system.