Please answer a question about the following article about Sexual orientation:

The Kinsey scale has been praised for dismissing the dichotomous classification of sexual orientation and allowing for a new perspective on human sexuality. However, the scale has been criticized because it is still not a true continuum. Despite seven categories being able to provide a more accurate description of sexual orientation than a dichotomous scale it is still difficult to determine which category individuals should be assigned to. In a major study comparing sexual response in homosexual males and females, Masters and Johnson discuss the difficulty of assigning the Kinsey ratings to participants. Particularly, they found it difficult to determine the relative amount heterosexual and homosexual experience and response in a person's history when using the scale. They report finding it difficult to assign ratings 2-4 for individuals with a large number of heterosexual and homosexual experiences. When, there is a lot of heterosexual and homosexual experiences in one's history it becomes difficult for that individual to be fully objective in assessing the relative amount of each.

How many categories are used in the KInsey scale?
seven