Task: Text Categorization
Input (English): Question: Why mechanism produces hyperprolactinemia haloperidol ?: 
 Options:  <0> Blockade of alpha 1 adrenergic receptors. <1> Blockade of alpha-2 adrenergic receptors <2> Blocking of H1 receivers. <3> Blockade of D2 receivers. <4> Blocking of 5-HT2 receptors.
Output (English): pharmacology