The term used here comes from home management studies, where several techniques are taught for using time and energy efficiently. The question is asking for the specific name of the technique where two activities are combined into the same time slot. Let's examine each option:
Only dovetailing specifically names the technique of combining two tasks into a shared time slot to conserve both time and energy; the other three terms describe something else entirely (an effect of work, a schedule, or a general category of effort reduction).
Therefore, the correct answer is Dovetailing.