Pie charts for the predicted numbers of pre-interaction MS OB stars primaries, and of OB stars in different types of post-interaction binaries, divided into three groups, Group 1 (top left; top right provides a zoom-in), Group 2 (lower left), and Group 3 (lower right), based on luminosities and effective temperatures. The considered types of binary stars and the corresponding fractions with respect to the total number within the considered group are indicated by text. The corresponding absolute numbers in each wedges are listed in Table 2.