Step 1: Understanding Kolkhoz.
Kolkhoz refers to a type of collective farming organization that was widely used in the former Soviet Union. The word "Kolkhoz" comes from the Russian terms "kollektivnoye khozyaystvo," meaning "collective farm." In this system, land was owned collectively, and farming was carried out through a joint effort by the workers.
Step 2: Exploring other options.
- Cooperative farming: This refers to farms where individual farmers work together, sharing resources and profits but still maintaining individual ownership.
- Plantation farming: This involves the cultivation of cash crops like tea, coffee, or rubber, typically on large estates.
- Karkhana farming: This term is unrelated to farming practices and refers to an industrial setup.
Step 3: Conclusion.
Kolkhoz refers specifically to collective farming, which is a system where farmers work together, pooling their resources and labor.
\[
\boxed{\text{Thus, the correct answer is Collective farming.}}
\]