10238
To examine this , pigeons were trained to discriminate the GABA ( B ) receptor - positive modulator ( R , S ) - 5 , 7 - di - tert - butyl - 3 - hydroxy - 3 - trifluoromethyl - 3H - benzofuran - 2 - one ( rac - BHFF ) from its vehicle .
 Chemical: GABA; Chemical: ( R , S ) - 5 , 7 - di - tert - butyl - 3 - hydroxy - 3 - trifluoromethyl - 3H - benzofuran - 2 - one; Chemical: rac - BHFF
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: GABA; Chemical: ( R , S ) - 5 , 7 - di - tert - butyl - 3 - hydroxy - 3 - trifluoromethyl - 3H - benzofuran - 2 - one; Chemical: rac - BHFF