Yeast is a fungus and it can die. bakers proof yeast to make sure it will respond and rise. a student tests different ways to proof yeast by adding it to warm water and other ingredients. if the yeast is alive, the mixture should appear bubbly after five minutes. the results are shown in the table. according to the data, what is the best substance to use when proofing yeast. a. yeast responds to added salt b. yeast responds to added sugar c. yeast responds to added water d. yeast responds to the presence of light