This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
The difference between contamination and infection is that in infection 
Select and explain. 
A. Infectious agent is on body surface or on non-human objects, B. Infectious agent is in the body of human, C. Ahropods on the body surface, D. Infectious agents on clothes
B: Infectious agent is in the body of human
Answer: B: Infectious agent is in the body of human 
Explanation: INFECTION The entry and development or multiplication of an infectious agent in the body of man / animals An infection doesn&;t always cause infection Levels of infection:- 1. Colonization- Staphylococcus aureus in skin and nasopharynx 2. Subclinical/inapparent infection- Polio 3. Latent infection- HSV 4. Manifest/clinical infection CONTAMINATION:- The presence of an infectious agent on a body surface, also on/in clothes, bed,toys, instruments or other inanimate substances including water, milk and food Reference: Park&;s textbook of Preventive and Social medicine; 23rd edition;, Page no. 92