This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
Sexually transmitted infection characterized by painful genital ulcers and lymph nodes: 
Select and explain. 
A. Syphilis, B. Chancroid, C. Herpes, D. Donovanosis
B: Chancroid
Answer: B: Chancroid 
Explanation: Ans. B. ChancroidSexually transmitted infectionsInfection/featureIncubation periodGenital ulcerLymphadenopathySyphilis9-90 daysPainless, indurated, SinglePainless, moderateHerpes2-7 daysMultiple, painfulAbsent/Moderate swellingChancroid1-14 daysPainful, soft, single/multiplePainful, soft, single/multiple marked swelling (Bubo)LGV3 days-6 weeksPainlessPainfulDonovanosis1-4 weeks (mat be up to 6 monthsPainless beefy red ulcerAbsent(subcutaneous swelling may look like pseudo bubo)