Answer : The correct option is, Light absorption
Explanation :
Microspectrophotometer : It is a type of instrument that measures the spectra of the microscopic sample by using the different wavelengths of an electromagnetic radiation.
It is designed to measure the the spectrum of the microscopic sample. It is also measure the transmittance, absorbance, polarization and fluorescence of the microscopic sample.
From the given options, the option light absorption is the correct option.
Hence, a microspectrophotometer measures the light absorption.