Fluorometers are designed so that the path of the excitation light is at a right angle to the path of the emitted light. What is the purpose of this design

prevent excitation light from reaching the detector

Explanation:

A fluorometer refers to the device that's used in the measurement of parameters that are of visible spectrum fluorescence. They also prevent excitation light from reaching the detector.

These parameters are used in the identification of the amount and presence of molecules in a medium.

it has to be b, about 97 percent.