A.I. Explanation:

Correct answer: complex

Explanation: The word 'complex' is an adjective that describes the noun 'system,' indicating that the world economy is intricate and multifaceted. This fits grammatically as it modifies the noun appropriately and aligns with the context of discussing the economy's nature.

Meaning: 'Complex' means consisting of many different and connected parts; intricate.

Wrong options:

• difficult: The word 'difficult' is an adjective that describes something hard to do or understand, but it does not appropriately describe the noun 'system' in this context.
• submit: The word 'submit' is a verb that means to present or propose something for consideration, which does not fit as a description of the economy.
• resent: The word 'resent' is a verb that means to feel bitterness or indignation at having been treated unfairly, which is unrelated to describing the economy.

Correct answer: consumption

Explanation: The term 'consumption' is a noun that fits grammatically in the series of economic activities (production, distribution, and consumption) and contextually describes the use of goods and services by consumers.

Meaning: 'Consumption' refers to the action of using up a resource or the purchase of goods and services by consumers.

Wrong options:

• submit: The word 'submit' is a verb that does not fit in the context of economic activities, as it does not relate to the use of goods and services.
• difficult: The word 'difficult' is an adjective that does not fit in this context, as it does not describe an economic activity.
• resent: The word 'resent' is a verb that does not relate to economic activities and does not fit grammatically.

Correct answer: topics

Explanation: The word 'topics' is a noun that fits grammatically as it serves as the object of the verb 'encompasses,' indicating what macroeconomics studies. It is contextually appropriate as it refers to various subjects within the field of economics.

Meaning: 'Topics' refers to subjects or themes that are discussed or studied.

Wrong options:

• difficult: The word 'difficult' is an adjective that does not fit as it cannot serve as an object in this context.
• submit: The word 'submit' is a verb that does not fit grammatically or contextually as it does not relate to subjects of study.
• resent: The word 'resent' is a verb that does not fit in this context, as it does not relate to the subjects studied in economics.

Correct answer: policies

Explanation: The word 'policies' is a noun that fits grammatically as it serves as the object of the verb 'developing,' indicating what is being created to address economic challenges. It is contextually appropriate as it refers to strategies or plans of action.

Meaning: 'Policies' refer to deliberate systems of principles to guide decisions and achieve rational outcomes.

Wrong options:

• difficult: The word 'difficult' is an adjective that does not fit as it cannot serve as an object in this context.
• submit: The word 'submit' is a verb that does not fit grammatically or contextually as it does not relate to the creation of strategies or plans.
• resent: The word 'resent' is a verb that does not fit in this context, as it does not relate to the development of strategies or policies.