Methicillin-resistant staphylococci do not respond to β-lactam antibiotics because:: (A) They produce a b-lactamase which destroys methicillin and related drugs., (B) They elaborate an amidase which destroys methicillin and related drugs., (C) They are less permeable to b-lactam antibiotics., (D) None of the above
Answer is B. Resistance to most penicillins is due to elaboration of beta-lactamase. 

Methicillin is most resistant penicillin to β-lactamase. 
Staphylococcus aureus develops resistance to methicillins by acquisition of altered penicillin binding proteins.