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
Pneumococcal resistance to penicillin G is mainly acquired by  : 
Select and explain. 
A. Conjugation, B. Transduction, C. Transformation, D. All of the above
C: Transformation
Answer: C: Transformation 
Explanation: Acquisition of antibiotic resistance by Transduction is common in Staphylococcal and that of by Transformation in Pneumococcus and Neisseria.
Vancomycin resistance in enterococci and Staphylococcus is mediated by the conjugative plasmid.