17899
OBJECTIVES : We conducted a within - subjects placebo - controlled study of a wide range of oral theobromine doses ( 250 , 500 , and 1 , 000 mg ) using an active control dose of caffeine ( 200 mg ) in 80 healthy participants .
 Chemical: theobromine; Chemical: caffeine
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: theobromine, caffeine 
Answer:
 Chemical: theobromine; Chemical: caffeine