7533
As the reduction of CO ( 2 ) proceeds through ET and then PT , the pyridine ring becomes aromatic , and thus Py catalyzes CO ( 2 ) reduction by stabilizing the PCET TS and the PyCOOH ( 0 ) product through aromatic resonance stabilization .
 Chemical: CO ( 2 ); Chemical: pyridine; Chemical: CO ( 2 ); Chemical: PyCOOH ( 0 )
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: CO ( 2 ), pyridine, CO ( 2 ), PyCOOH ( 0 ) 
Answer:
 Chemical: CO ( 2 ); Chemical: pyridine; Chemical: CO ( 2 ); Chemical: PyCOOH ( 0 )