Which is an example of a vestigial structure? A) The flipper of a whale
B) The wings of a bird
C) The tailbone of a human
D) The eyes of a bat

C) the tailbone of a human

Humans no longer have tails due to evolution because we don't need them. The other answers are body parts that are useful to those animals.

Hope this helps!

"menstrual cycle is a complex cycle that consists of several processes. order of occurrence of steps in menstrual cycle are as follows:

1. high progesterone levels maintain the endometrium lining of the uterus.

2. endometrium lining breaks down and low levels of estrogen stimulate the pituitary to release fsh and lh.

3. fsh and lh stimulates the follicles to develop and the oocyte to produce estrogen.

4. rising estrogen levels suppress fsh production and development of other follicles.

5. a spike in lh causes follicle to rupture.

6. a breakdown of corpus luteum causes progesterone level to drop."