The passage of radiation through matter without interaction is described as:

• A. Convergence
• B. Divergence
• C. Attenuation
• D. Transmission

Answer: (D)

The main idea here is distinguishing how radiation interacts with matter from how it travels beyond it. When radiation passes through material without interacting at all, the beam is described as transmitted. In this ideal case, the photons keep their energy and direction intact as they emerge on the other side.

Attenuation, in contrast, refers to the overall reduction in beam intensity caused by interactions such as absorption or scattering within the material. Divergence and convergence describe changes in the beam’s geometry—whether it spreads out or is focused—as it travels, which are about shape and direction rather than whether any interaction occurred. So the term that matches “passage through matter without interaction” is transmission.