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: Radiology
According to Heel effect: 
Select and explain. 
A. High intensity x-rays are found at cathode., B. Low intensity x-rays are found at anode., C. Both of the above., D. None.
C: Both of the above.
Answer: C: Both of the above. 
Explanation: According to “Heel effect”, when cathode rays strike anode target, X-rays with high intensity are found towards cathode side of central ray and X-rays with low intensity are found towards anode. This is due to self absorption of photons in the anode target.