Angle Class I occlusion exists when the mesiobuccal cusp of the permanent maxillary first molar occludes

in the buccal groove of the permanent mandibular first molar.

distal to the buccal groove of the permanent mandibular first molar.

mesial to the buccal groove of the permanent mandibular first molar.

lingual to the mesiobuccal cusp of the permanent mandibular first molar