Members of the fungus-like genus Phytophthora are responsible for many crop diseases that threaten plants around the

Question:

Members of the fungus-like genus Phytophthora are responsible for many crop diseases that threaten plants around the world. Sexual reproduction for this genus is modulated by a mating hormone, shown below:

a. How many stereogenic centers are present in this compound?
b. Draw structures for the unique stereoisomers of this hormone and provide the name of each structure.