This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
Monocytes, macrophages, and lymphocytes secrete chemicals, called as 
Select and explain. 
A. Monokines, B. Cytokines, C. Lymphokines, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: (Refer: Robbins & Cotran's - Pathologic Basis of Disease, SAE, 1st edition, Vol I-pg no: 86& 196)