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
Commonest location of Spigelian hernia is at: 
Select and explain. 
A. At Arcuate line, B. Above arcuate line, C. Both of the above, D. None of the above
C: Both of the above
Answer: C: Both of the above 
Explanation: Spigelian hernias can occur anywhere along the length of the Spigelian line or zone--an aponeurotic band of variable width at the lateral border of the rectus abdominis. However, the most frequent location of these rare hernias is at or slightly above the level of the arcuate line. These are not always clinically evident as a bulge and may come to medical attention because of pain or incarceration. Ref: Schwaz's principle of surgery 9th edition, chapter 35.