Why are children more sensitive to radiation?

Children are more sensitive to radiation primarily because their cells are rapidly dividing. This rapid cell division is crucial for growth and development, especially in early years. When radiation exposure occurs, it can cause damage to DNA and interfere with the normal processes of cell division and growth. Because children's tissues and organs are still developing, they are more vulnerable to the harmful effects of radiation, which can lead to an increased risk of cancer and other health issues later in life.

The other options do not accurately reflect the biological reasons for children's heightened sensitivity. Age itself does not correlate with greater damage in this context; rather, it is the active state of cell division in children that leads to increased susceptibility. Furthermore, while a strong immune system is beneficial for combating illness, it does not provide protection against the damaging effects of radiation. Lastly, the absorption of radiation does not significantly differ between children and adults; rather, it is the biological effects resulting from that absorption that make children more sensitive.