The correct answer is D) operates without energy absorbing intake and exhaust strokes. A two-stroke cycle diesel engine requires less starting air than a four-stroke cycle diesel engine of equal displacement because it operates without the energy-absorbing intake and exhaust strokes. In a two-stroke cycle engine, the intake and exhaust functions are combined, eliminating the separate intake and exhaust strokes present in a four-stroke cycle engine. This allows the two-stroke cycle engine to operate with a higher effective compression ratio and less internal friction, requiring less starting air to initiate combustion compared to a four-stroke cycle engine of the same displacement. The other answer choices are incorrect because they do not accurately explain the reason why a two-stroke cycle diesel engine requires less starting air. Specifically, options A and B are not the primary reasons, while option C describes a characteristic of the two-stroke cycle, but does not directly explain the reduced starting air requirement.