This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Which of the following is false about vaginal hydrocele 
Select and explain. 
A. Transillumination is always positive, B. It can occur secondary to epididymo-orchitis, C. Patent processus vaginalis is a risk factor, D. Most common cause is idiopathic
B: It can occur secondary to epididymo-orchitis
Answer: B: It can occur secondary to epididymo-orchitis 
Explanation: Not all hydrocele are transillumination positive.
Secondary hydrocoele have turbid fluid collection.