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: Medicine
Rx of latent syphilis  a) Penicillin  b) Erythromycin  c) Tetracycline  d) Ciprofloxacin 
Select and explain. 
A. ac, B. ab, C. bc, D. bd
A: ac
Answer: A: ac 
Explanation: None