The primary difference between absorbed dose (D) and equivalent dose (EqD) is that the equivalent dose takes into account the:

The primary difference between absorbed dose (D) and equivalent dose (EqD) is that the equivalent dose takes into account the:

• A. Tissue type
• B. Exposure rate
• C. Person's age
• D. Radiation type

Answer: (D)

The key idea is that equivalent dose adjusts for how damaging different radiation types are. Absorbed dose tells you how much energy is deposited in tissue per unit mass, without regard to the kind of radiation. To get the equivalent dose, you multiply that absorbed dose by a radiation weighting factor that reflects the biological effectiveness of the radiation type. High‑LET radiations like alpha particles cause more harm per unit energy than low‑LET radiations like X‑rays or gamma rays, so they get higher weighting factors and a larger equivalent dose for the same energy deposition. The other options don’t adjust for radiation quality in the same way: tissue type affects risk in broader dose concepts, exposure rate isn’t part of the calculation, and age isn’t part of the equivalent dose.

The key idea is that equivalent dose adjusts for how damaging different radiation types are. Absorbed dose tells you how much energy is deposited in tissue per unit mass, without regard to the kind of radiation. To get the equivalent dose, you multiply that absorbed dose by a radiation weighting factor that reflects the biological effectiveness of the radiation type. High‑LET radiations like alpha particles cause more harm per unit energy than low‑LET radiations like X‑rays or gamma rays, so they get higher weighting factors and a larger equivalent dose for the same energy deposition. The other options don’t adjust for radiation quality in the same way: tissue type affects risk in broader dose concepts, exposure rate isn’t part of the calculation, and age isn’t part of the equivalent dose.