The ischiococcygeus and sacrococcygeus muscle are not considered part of the levator ani muscle group, but they do contribute to the structure and function of the pelvic diaphragm. I think upsc mark this question as a bonus.

Q.95. Consider the following statements about correlation between two variables: 1. The correlation is done between an independent variable X and a dependent variable Y. 2. The coefficient of correlation can range from 1 to ∞. 3. If coefficient of correlation (r) is equal to 1, it indicates there is no association between X and Y. 4. Correlation does not necessarily prove causation. Which of the statements given above is are correct? (a) 1 only (b) 4 only (c) 1, 2 and 3 (d) 1 and 4 only Answer is B:- 4 only.