A. Buccals slopes of buccal cusps of maxillary posterior teeth
B. Buccal slopes of lingual cusps of maxillary posterior teeth
C. Lingual slopes of lingual cusps of mandibular posterior teeth
D. All slopes of lingual cusps of mandibular posterior teeth
✅ The correct answer is option B. Buccal slopes of lingual cusps of maxillary posterior teeth.