Drew added yeast and sugar to lukewarm water and placed it in a flask. He stretched a balloon over the opening of the flask. After several minutes, he noticed
small bubbles rising along the side of the flask as the balloon slowly began to inflate.
Drew concluded that -

A)a physical change was occurring

B) the bubbles indicated a chemical change

C) the water surger and yeast were products of a chemical reaction

D) the strong smell was evidence of a physical changer