Task: Text Categorization
Input (English): Question: From what compound and where mainly melatonin is produced ?: 
 Options:  <0> From tyrosine in the skin. <1> From tryptophan in the skin <2> From tryptophan in the pineal gland. <3> From tyrosine in the pituitary gland. <4> From tyrosine in the pineal gland.
Output (English): pharmacology