Explanation:

- Factors of production: These are resources used to produce goods and services, such as land, labor, and capital. Although related to Marxist theory, the term "social formation" doesn't directly refer to them.

- Relations of production: These refer to the relationships between different classes in the production process. These are crucial in Marxism but don't directly equate to "social formation."

- Change in society: This involves social evolution and transformation, important in Marx’s work, but "social formation" is not specifically this.

- Mode of production: This is the combination of productive forces and relations of production. It shapes a society's socio-economic structure and is closest to what Marx means by “social formation.”