Task: Question Answering
Input (English): Question: What is the relationship between turbidimetry and nephelometry? 
 Options:  <1> Nephelometry is the inverse of turbidimetry. <2> Turbidimetry is more sensitive than nephelometry. <3> Nephelometry can be measured with a conventional spectrophotometer. <4> Both technologies measure the dispersion of light. <5> Both technologies are the most sensitive and used in clinical laboratories.
Output (English): 4