Task: Text Categorization
Input (English): Question: The absorbance of a medium solution at the isosbestic point is that determined to: 
 Options:  <0> The wavelength at which the molar absorption coefficients of two absorbent species in chemical equilibrium, interconvertible to each other, are equivalent. <1> The wavelength at which the molar absorption coefficients of two absorbing species in chemical equilibrium are not equivalent. <2> The wavelength at which the acid form of an indicator is maximum. <3> The wavelength at which the acid form of an indicator is minimal. <4> The wavelength of the species that participate in the equilibrium when it is displaced towards longer wavelengths.
Output (English): pharmacology