This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Musculo Skeletal Disorders, Subject name: Pediatrics
Which of these muscles is most frequently affected in childhood poliomyelitis? 
Select and explain. 
A. Quadriceps, B. Deltoid, C. Tibialis anterior, D. Biceps
A: Quadriceps
Answer: A: Quadriceps 
Explanation: Ans. A. QuadricepsThe most frequently affected muscles in poliomyelitis (in order of the frequency with which they are affected)(Lower limb muscles - Quadriceps; tibialis anterior; peroneal muscles) > (Upper limb muscles - Deltoid; triceps; biceps) > (Trunk - abdominal muscles; back; intercostals; diaphragm)