Explanation:

Here’s what’s going on with Marx’s concept of alienation and where he talked about it:

- Alienation is one of Marx’s big ideas—it's about how workers become disconnected from their work, themselves, and each other under capitalism.

- The main place Marx spells this out is in the Economic and Philosophic Manuscripts of 1844. This is where he goes all-in describing what alienation feels like and means for real people.

- Das Kapital is more about how capitalism works as a system—values, commodities, surplus value—but it doesn’t focus as much on alienation as a concept. It’s there, but not the centerpiece.

- The Communist Manifesto is more of a rallying cry and summary; it touches on exploitation but doesn’t dwell on alienation.

- There’s no book called “Power of philosophy” by Marx.

So, now the options:

- Option 1: 1,4 (Das Kapital, Economic and Political Manuscripts)

- Option 2: 2,3 (Manifesto, Power of philosophy)

- Option 3: 3,4 (Power of philosophy, Economic and Political Manuscripts)

- Option 4: 1,4 (Das Kapital, Economic and Political Manuscripts)

The best answer is:

Option: 4, 1,4 (Das Kapital and Economic and Political Manuscripts).