What is the threshold dose for deterministic effects of radiation?

The threshold dose for deterministic effects of radiation is characterized as the level of exposure at which specific effects first become noticeable and above which more severe effects may occur. This concept indicates that there is a minimum dose an individual must receive before the effects manifest; below this threshold, the individual is not expected to exhibit any deterministic reactions.

In the context of radiation, deterministic effects are those that have a direct correlation between the dose received and the severity of the effect, such as skin damage or radiation sickness. As the dose increases beyond this threshold, the likelihood and severity of these effects increase. Therefore, option B accurately describes this principle, emphasizing that no effects are observed below this critical level of exposure.

The remaining choices address different aspects of radiation effects that do not pertain directly to the deterministic threshold. For instance, while severe effects indeed occur above a certain dose, this does not specifically define the threshold itself. The notion of genetic mutations and increased cancer risk pertains to stochastic effects, which do not have a defined threshold and can occur at any level of exposure, albeit with varying probabilities.