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: Pharmacology
SeICIDs are derivatives of: 
Select and explain. 
A. Chloroquine, B. Retinoic acid, C. Thalidomide, D. None of the above
C: Thalidomide
Answer: C: Thalidomide 
Explanation: Another group of thalidomide analogs, selective cytokine inhibitory drugs (SelCIDs), are phosphodiesterase type 4 inhibitors with potent anti-TNF-a activity but no T-cell co-stimulatory activity. Several SelCIDs are currently under investigation for clinical use. Ref: Katzung 11th edition Chapter 61.