In this task, you are given a question and answer options for that question. Using this information, you have to classify each text into different topics: medicine, nursery, psychology, chemistry, pharmacology, biology.

Question: A basic component of spectrophotometers is the monochromator. Its function is: 
 Options:  <0> Connect the different wavelengths from the source to achieve greater light power. <1> Transform the optical signal measured by the detector into an electrical signal. <2> Disperse the light separating the wavelengths that compose it and select a narrow band. <3> Amplify the analytical signal by improving the signal-to-noise ratio. <4> Decrease the power of the light beam to eliminate the background noise of the spectrophotometer.
chemistry

Question: The epithelium of the epidermis is: 
 Options:  <0> Stratified keratinized plane. <1> Stratified non-keratinized plane. <2> Simple keratinized cylindrical. <3> Keratinized stratified cylindrical. <4> Cubic stratified.
biology

Question: The presence of phosphatidylserine on the cell surface indicates: 
 Options:  <0> Cellular senescence <1> Apoptosis <2> Necrosis. <3> Mitosis. <4> Hormone stimulation

biology