This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Anti-carcinogens are: (PGI Dec 2007) 
Select and explain. 
A. Carotenoids, B. Flavenoids, C. Curcumoids, D. Benzene
A: Carotenoids
Answer: A: Carotenoids 
Explanation: Ans: A (Carotenoids) Cancer Chemoprevention: Agents used Harrison 17th/488-89 # Premalignant lesions in the oropharyngeal area have responded to retinal/ a-tocopherol (vitamin E)Q, and selenium Q b carotene( a carotenoid) may decrease the incidence of lung, esophagus, and stomach cancer (in accordance with various trials, but the definite evidence is lacking)- CMDT09/1424 Nonsteroidal anti-inflammatory drugs (NSAIDs). such as piroxicam, sulindac, and aspirin, may prevent adenoma formation or cause regression of adenomatous polyps. Diets high in calcium lower colon cancer risk Atrial comparing tamoxifen Q with another selective estrogen receptor modulator, raloxifene, showed that raloxifene is comparable to tamoxifen in cancer prevention. FinasterideQ, a 5-a-reductase inhibitor is used in prostate cancer prevention. Selenium is being tested as a prostate cancerQ preventive based on laboratory studies, epidemiologic data, and a small randomized skin cancer prevention trial that showed a significantly decreased number of prostate cancers in men taking selenium