During the Luteal Phase a Low Level of Progesterone and Estrogen

During the luteal phase a low level of progesterone and estrogen will bring about

A) the disintegration of the endometrium and the rupturing of the blood vessels.
B) the thickening of the endometrial lining in preparation for the implantation of a zygote.
C) the development of a secondary oocyte.
D) a spike of the lutenizing hormone causing the oocyte to be ovulated.
E) the enlarging of the breast tissue in order to prepare for lactation.