In the female, the pelvic floor (outlet) is penetrated by the urethra, vagina, and

The correct answer would be the anus.  

Explanation:

The perineum is a diamond shaped region in the body that carries genitals and anus that protects it. It is made by perineum muscles which make the pelvic floor (outlet) and that can be divided into 2 diamond shape area or triangles which is an anus triangle and urogenital triangle.

The pelvic floor is penetrated by the urethra, vagina, and anus in a female and penetrated by urethra and anus in males. This is why the pelvic floor is essential for obstetrics.

Thus, the correct answer is the anus.