How does a pure command economy answer the basic question of which goods and services should be produced?

The consumers decide what should be produced.
The government decides what should be produced.
The law of supply and demand drives this choice.
The producers decide what should be produced.

The government decides what should be produced. In a pure command economy, all economic decisions are made by the central government or a central planning authority. The government determines what goods and services should be produced based on national priorities, goals, and objectives, rather than leaving it up to individual consumers or producers.