Following Is the Structure for PGF_{2 $\beta$} What Structural Feature Is Represented by 2

Following is the structure for PGF_{2 $\beta$} What structural feature is represented by 2 $\beta$ ?

A) 2 represents the number of double bonds
B) $\beta$ represents the trans relationship between the two OH groups
C) $\beta$ represents the trans relationship between the side chains
D) A & C
E) A & B