Answer:
The answer is Estrogen.
Step-by-step explanation:
The hormone that causes the new growth of the endometrial lining of the uterus is ESTROGEN. During the first days of menstruation, estrogen levels are low; In the middle of the follicular phase the follicle that is going to ovulate has already been selected, is when estrogen levels begin to rise. It is considered as an index of the fertile period of the menstrual cycle. Glandular proliferation occurs at the endometrial level (Proliferative phase).