A: Pressure.
The body has specialized receptors that can detect pressure, such as the mechanoreceptors found in the skin and inner ear.
B: Polarization.
The body cannot detect polarization, as this is a physical property of light and electromagnetic waves that is not directly perceptible by the human body.
C: Radiation.
The body cannot directly detect all forms of radiation, such as ionizing radiation, which can be harmful. However, the body can detect certain types of radiation, such as visible light, which is detected by the eyes.
D: Radioactivity.
The body cannot directly detect radioactivity, as this is a property of atomic nuclei that is not directly perceptible by the human body. However, exposure to ionizing radiation can cause damage to cells and tissues, which can be detected through various biological effects.