21509
Experimental design was conducted under 0 , 5 , 10 , 25 , 50 , 100 , 125 , and 150 ppm B exposures , and physiological changes have revealed a sharp decrease in root growth rates from 28 % to 85 % , starting from 25 ppm to 150 ppm , respectively .
 Chemical: B
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: B