Which material can effectively block neutron radiation?

To effectively block neutron radiation, materials with high hydrogen content are typically utilized, as neutrons are easily moderated by hydrogen atoms. Concrete and water are particularly effective due to their ability to slow down neutrons, making option D partially accurate since concrete is included, and water is recognized for its high hydrogen content.

However, it should be noted that lead is not an effective shielding material for neutron radiation specifically; it is more effective for gamma radiation. This makes option C also viable, as concrete and earth can provide adequate shielding by scattering and absorbing neutrons.

Ultimately, materials that contain hydrogen, like water and concrete, are essential for neutron shielding. Therefore, while option D includes water and concrete, which are both effective, the inclusion of oil as a material for neutron shielding is less scientifically supported.

In summary, neutron radiation shielding requires materials rich in hydrogen, where concrete and water are key, while options that suggest materials such as skin and clothing lack the necessary density and composition for effective neutron blocking.