Who wrote the famous economic and political treatise Das Kapital on capitalism and class struggle?

Introduction / Context:
"Das Kapital" is one of the most important works in economic and political theory. It analyses the capitalist system, surplus value, exploitation, and class struggle. Written in the nineteenth century, it has influenced political movements and economic thought across the world. This question checks whether the learner can correctly identify the author of this major work, which is a standard item in political science and economics general knowledge.

Given Data / Assumptions:

• The book title is "Das Kapital".
• The subject is capitalism, class relations, and economic theory.
• The options are Max Weber, Karl Marx, Adam Smith, and Vladimir Lenin.
• Only one of these thinkers authored "Das Kapital".

Concept / Approach:
To answer this correctly, it is important to associate each thinker with their main works. Adam Smith is linked with "The Wealth of Nations", Max Weber with works like "The Protestant Ethic and the Spirit of Capitalism", and Vladimir Lenin with writings on revolutionary practice and state theory. "Das Kapital" belongs to Karl Marx, who developed a critique of political economy and examined the dynamics of capitalism. Matching the correct work to the correct thinker is the central approach here.

Step-by-Step Solution:
Step 1: Recognise that "Das Kapital" is a multi volume work that studies capitalism, labour, and surplus value. Step 2: Recall that Karl Marx, a German philosopher and economist, wrote this treatise to analyse the capitalist mode of production. Step 3: Compare this with the other options. Adam Smith predates Marx and is known for classical liberal economics, while Max Weber and Vladimir Lenin belong to different later contexts. Step 4: Confirm that Marx is widely cited as the author of "Das Kapital" in textbooks and reference works. Step 5: Choose Karl Marx as the correct answer.

Verification / Alternative check:
A common check is to recall how the names of these thinkers appear together in history. For example, "The Wealth of Nations" is always linked to Adam Smith, "Das Kapital" and "The Communist Manifesto" are linked to Karl Marx, while Lenin is associated with works on revolutionary strategy such as "What Is to Be Done". Max Weber is known for sociological analysis of religion and bureaucracy. Since "Das Kapital" is consistently attributed to Karl Marx in academic and popular sources, this confirms the answer.

Why Other Options Are Wrong:
Max Weber: He contributed to sociology and wrote about the relationship between religion and capitalism, but he did not author "Das Kapital".
Adam Smith: He is regarded as a founder of classical economics and wrote "An Inquiry into the Nature and Causes of the Wealth of Nations", not "Das Kapital".
Vladimir Lenin: He built on Marxist ideas and wrote many works on revolutionary practice, but he did not write "Das Kapital"; he interpreted and applied Marx's theory.

Common Pitfalls:
Some learners confuse economic thinkers and may attribute every famous book on capitalism to Adam Smith or any Marxist work to Lenin. Another pitfall is to focus only on the general theme of capitalism and then guess randomly among names associated with political and economic thought. It is important to remember specific core works associated with each thinker, such as linking "Das Kapital" clearly with Karl Marx.

Final Answer:
The author of "Das Kapital" is Karl Marx.