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: Medicine
Which is NOT a function of muscles? 
Select and explain. 
A. Cause movement, B. Produce heat, C. Absorb nutrients, D. Maintain posture
C: Absorb nutrients
Answer: C: Absorb nutrients 
Explanation: Option C: This is a function of the digestive system. Transport of digested end products from the lumen of the GI tract to the blood or lymph is absorption, and for absorption to happen, the digested foods must first enter the mucosal cells by active or passive transport processes.
Options A, B, and D: These are functions of the muscular system.