17.Radiations are absorbed in

Explanation

The correct answer to the question "Radiations are absorbed in" is:(a) Spectrophotometer methodHere's why the other options are incorrect:(b) Dilatometric method: This method measures changes in the dimensions of a material due to thermal or chemical expansion/contraction. It doesn't involve absorption of radiation.(c) Optical relation method: This is not a well-defined term in standard chemical or analytical methods. It's unclear what kind of "radiations" this method would involve absorbing.(d) Refractometric method: This method measures the refractive index of a material, which relates to how light bends when passing through it. While refractometers use light sources, they don't involve the absorption of radiation by the analyte.