The Concerned Economist:

- The question asks who among the given options is concerned with the `welfare definition` of economics.
- This suggests that the question is referring to the different definitions of economics - some of which may prioritize efficiency, while others may prioritize equity and welfare.
- Therefore, the answer must be someone who is known to have advocated for or emphasized the importance of welfare in economics.

Prof. Marshall:

- This option is the correct answer because Alfred Marshall is known for his welfare-oriented approach to economics.
- Marshall believed that economics should not just focus on maximizing individual utility or profit, but should also consider the social welfare implications of economic activity.
- He introduced the concept of consumer surplus, which measures the difference between what a consumer is willing to pay for a good and what they actually pay, as a way to measure welfare gains from trade.
- Marshall also argued that economic policies should be evaluated based on their ability to improve social welfare, rather than just on their ability to promote economic growth or efficiency.

Prof. Samuelson:

- Although Paul Samuelson is a notable economist, he is not typically associated with the welfare definition of economics.
- Samuelson is known for his contributions to neoclassical economics, which emphasizes efficiency and rationality in economic decision-making.
- However, Samuelson did acknowledge the importance of welfare considerations in economics, particularly in his later work.

Adam Smith:

- Adam Smith is often considered the founder of modern economics, but his views on welfare are somewhat ambiguous.
- Smith believed that economic growth and efficiency were important goals, but he also recognized the importance of social welfare and justice.
- However, Smith's emphasis on the invisible hand and self-interest have led some to view him as a proponent of laissez-faire economics.

Lord Robbins:

- Lord Robbins is best known for his definition of economics as "the science which studies human behavior as a relationship between ends and scarce means which have alternative uses."
- While this definition does not explicitly prioritize welfare, Robbins did acknowledge the importance of ethical considerations in economics.
- Robbins argued that economics should not just describe how people behave, but should also consider how they ought to behave in order to achieve social welfare.

Answer: A. Prof. MarshallExplanation:- The welfare definition of economics is primarily associated with Prof. Alfred Marshall, a British economist.- Prof. Marshall's definition of economics focuses on the study of wealth and its impact on human welfare.- In his book, "Principles of Economics," he defines economics as "a study of mankind in the ordinary business of life; it examines that part of individual and social action which is most closely connected with the attainment and with the use of the material requisites of wellbeing." Key Points:- Prof. Marshall's welfare definition emphasizes the importance of wealth in improving human welfare.- This definition considers both individual and social aspects of economic activities.- The welfare definition was prevalent in the late 19th and early 20th centuries but was later challenged by other definitions, such as the scarcity definition by Lord Robbins.