3943
When both skin test and RAST for BPO were negative , single - blind , placebo - controlled challenge tests were done to ensure tolerance of PG or sensitivity to AX .
 Chemical: BPO; Chemical: PG; Chemical: AX
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
 Entities: BPO, PG, AX 
Answer:
 Chemical: BPO; Chemical: PG; Chemical: AX