This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Air, Light, Sound, Housing, Radiation, Waste Disposal, Subject name: Social & Preventive Medicine
In fetus, Deterministic effects due to radiation are less likely to occur below the dose of ? 
Select and explain. 
A. 0.50 Gy, B. 5 Gy, C. 0.005 Gy, D. 0.50 rads
A: 0.50 Gy
Answer: A: 0.50 Gy 
Explanation: Biological effects of radiation: As exposed dose increases, Threshold dose Effects Deterministic effects/ Non-stochastic effects Severity of effect increases Yes - For fetus - 0.50 Gy (50 rads) - Includes all harmful tissue reactions, excluding stochastic effects. Stochastic effects Frequency of occurrence increases No - Genetic influence, carcinogenesis