The term "rem" is an abbreviation for what?

The term "rem" stands for "Roentgen equivalent man." This unit is used to measure the biological effect of ionizing radiation on human beings. It incorporates the idea that different types of radiation have varying impacts on human tissue, allowing for a more accurate assessment of risk associated with exposure. Named after the physicist Wilhelm Roentgen, the rem provides a way to quantify the potential harm from radiation exposure while considering the type of radiation and its interaction with biological systems.

The other choices do not accurately reflect the definition or application of the term "rem." "Radiation exposure measurement," while related, does not specify the biological context that "rem" entails. "Remnant radiation" refers to residual radiation that may remain after a radiological procedure, and "radiation equivalent measurement" is a descriptor but does not capture the historical context or specific intent behind the term "rem."