Task: Instance Description Understanding (ontology: Sciences/Biology)

Which of the following definitions best describes the instance 'sixty-nine'?

A. A group of sex positions in which two people align themselves so that each person's mouth is near the other's genitals, each simultaneously performing oral sex on the other. The participants are thus mutually inverted like the numerals 6 and 9 in the number 69, hence the name.
B. The performance of anal sex and refraining from vaginal sex in order to remain a "virgin"; typically pursued for religious reasons.
C. Offensive term often used in pornography to describe trans women.
D. Precoital or coital vaginal secretions.

Answer: A group of sex positions in which two people align themselves so that each person's mouth is near the other's genitals, each simultaneously performing oral sex on the other. The participants are thus mutually inverted like the numerals 6 and 9 in the number 69, hence the name.