This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
Which antibiotic acts by inhibiting protein synthesis 
Select and explain. 
A. Cefotetan, B. Doxycycline, C. Ciprofloxacin, D. Oxacillin
B: Doxycycline
Answer: B: Doxycycline 
Explanation: Ref Goodman Gilman 11/e p 1173 Doxycycline is a tetracycline that act by inhibiting protein synthesis Cefotetan and oxacillin are beta lactam antibiotics that act by inhibiting cell wall synthesis Ciprofloxacin is a Fluroquinolone that acts by inhibiting DNA gyrase