Most constant and valuable trait to differentiate among maxillary 1st , 2nd and 3rd molars is
(A) Relative position of DL groove (B) Relative position of ML groove (C) ML cusp size (D) Oblique ridge size
(A) Relative position of DL groove is most constant and valuable trait. As DL cusp becomes smaller as we move distally from 1st molar to 3rd molar.