1637
According to available positron emission tomography ( PET ) imaging analysis using [ ( 11 ) C ] ( - ) - cocaine and [ ( 11 ) C ] ( + ) - cocaine tracers in human subjects , only [ ( 11 ) C ] ( - ) - cocaine was observed in the brain , whereas no significant [ ( 11 ) C ] ( + ) - cocaine signal was observed in the brain .
 Chemical: [ ( 11 ) C ] ( - ) - cocaine; Chemical: [ ( 11 ) C ] ( + ) - cocaine; Chemical: [ ( 11 ) C ] ( - ) - cocaine; Chemical: [ ( 11 ) C ] ( + ) - cocaine
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: [ ( 11 ) C ] ( - ) - cocaine, [ ( 11 ) C ] ( + ) - cocaine, [ ( 11 ) C ] ( - ) - cocaine, [ ( 11 ) C ] ( + ) - cocaine 
Answer:
 Chemical: [ ( 11 ) C ] ( - ) - cocaine; Chemical: [ ( 11 ) C ] ( + ) - cocaine; Chemical: [ ( 11 ) C ] ( - ) - cocaine; Chemical: [ ( 11 ) C ] ( + ) - cocaine