Which of the following cusps are present on a mandibular first molar?

The mandibular first molar is characterized by having five cusps, which are essential for the mastication process. The correct answer includes the mesiolingual, mesiofacial, distolingual, distofacial, and distal cusps, which are all prominent on this specific tooth.

To understand the anatomy better, the mesiolingual cusp is typically larger and plays a major role in occlusion, as does the mesiofacial cusp. The distolingual and distofacial cusps help in stabilizing the tooth during chewing. The distal cusp aids in the overall contour of the tooth and its functional relationships with the opposing arch.

The other choices do not accurately represent the complete cusp morphology of the mandibular first molar. For instance, options mentioning fewer than five cusps miss important anatomical features and do not reflect the tooth's complex anatomy. Thus, the answer providing a comprehensive list of the cusps present is the most accurate representation of the mandibular first molar's structure.