Task: Question Answering
Input (English): Question: It is UV visible molecular absorption spectroscopy is called isosbestic point a: 
 Options:  <1> The region of the spectrum where two species have the same radiation emission capacity. <2> The pH at which two absorbing species have the same molecular absorption coefficient. <3> The temperature at which two absorbing species in equilibrium stop emitting radiation. <4> The wavelength at which two absorbing species in equilibrium has the same refractive index. <5> The wavelength at which the molecular absorption coefficients of two absorbent species in equilibrium, interconvertible to each other, are equivalent.
Output (English): 5