All are true regarding endometriosis, except:
Whatever the inital genesis of endometriosis its further development depends mainly on estrogen (Option “a”).
 It can occur anywhere in body, Most common site being ovary(Option “d”). 
 Can also involve lungs and pleura (Option “b”). 
 In endometriosis ovary contains tarry dark brown fluid (due to presence of blood pigments like hemosiderin) and cul de sac has yellow brown fluid.

Clear fluid is not seen anywhere, So, Option “c” is incorrect.
Hormone dependent condition
Can involve lung, pleura
Contains clear fluid
Ovary is the most common site