The three basic questions in economics are all of these, except 2 options: what to produce.how to produce.when to produce.for whom to produce.

When to produce

Explanation: Three basic questions in economics are - what to produce? , how to produce ? and for whom to produce ?

What to produce deals with what type of goods, whether luxury or necessity, should be produced.

How to produce deals with the method of production.

For whom to produce deals with the problem of which section of the society does production should be done.