What are the two main types of biological effects caused by radiation?

The correct choice highlights the distinction between deterministic effects and stochastic effects, which are crucial categories in understanding radiation's biological impact. Deterministic effects are those that occur above a certain threshold dose of radiation and have a severity that increases with the dose received. Examples of these effects include skin burns or radiation sickness, which can manifest shortly after exposure.

Stochastic effects, on the other hand, occur as a result of low-level radiation exposure and are characterized by the probability of occurrence rather than severity. These effects, such as cancer and genetic mutations, can manifest years after exposure, and the risk increases with the dose but does not have a definite threshold.

The other options, while they address different aspects of biological responses, do not capture the primary classification used to categorize radiation effects in terms of dose response and health implications. Acute and chronic effects refer to timing but do not provide insights on how the severity of the effects relates to dose. Transient and latent effects also focus on timing without encompassing the underlying mechanisms of radiation's impact. Synergistic and antagonistic effects involve interactions of multiple factors rather than categorizing radiation's direct biological effects.