Use the Graph Below, Which Shows Changes During the Menstrual $\mathrm{B}$

Use the graph below, which shows changes during the menstrual cycle, to answer the following Questions

-Blood levels of which substance are described by curve $\mathrm{B}$ ?

A) Estradiol
B) Estriol
C) Progesterone
D) Follicle-stimulating hormone (FSH)
E) Luteinizing hormone (LH)