Which Pattern Characterizes the Distinction Between Heterosexual and Homosexual Orientations

Which pattern characterizes the distinction between heterosexual and homosexual orientations

A)  They are each midpoints on their own scales, and cannot be directly compared. 
B)  They have no clear distinguishing characteristics other than self-report. 
C)  They are endpoints on a continuum, with intermediate orientations in between. 
D)  They are mutually exclusive categories, with clear boundaries.