Which of these is the function of Decidua basalis of the endometrium?

The superficial two thirds of endometrium is known as decidua functionalis. This layer undergoes monthly proliferative changes (in follicular phase) in response to estrogen and secretory changes (in secretory phase) in response to progesterone. Lower one third of endometrium, known as decidua basalis, does not undergo significant monthly proliferation, but instead is the source of endometrial regeneration after each menses.