16637
While some histopathological changes detected in liver tissues in chlorpyrifos treated group , less histopathological changes were observed in catechin + chlorpyrifos and quercetin + chlorpyrifos treated groups at the end of the 4thweek .
 Chemical: chlorpyrifos; Chemical: catechin; Chemical: chlorpyrifos; Chemical: quercetin; Chemical: chlorpyrifos
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: chlorpyrifos, catechin, chlorpyrifos, quercetin, chlorpyrifos 
Answer:
 Chemical: chlorpyrifos; Chemical: catechin; Chemical: chlorpyrifos; Chemical: quercetin; Chemical: chlorpyrifos