One student group's data for amount of yeast can be seen here. describe the students' results. a) the optimum amount of yeast for maximum fermentation is 2 grams. b) there is no correlation between amount of yeast and the rate of fermentation. c) there is a inverse relationship between the rate of fermentation and amount of yeast. d) there is a direct relationship between the amount of yeast and the rate of fermentation.

Option D, There is a direct relationship between the amount of yeast and the rate of fermentation.

Explanation:

The rate of fermentation increases till the time an optimum stage is not reached . Once the optimum stage is reached , any further increase in yeast concentration do not affect fermentation rate. Thus, it can be said that before reaching optimal value of yeast concentration, the rate of fermentation is directly proportional to the yeast concentration.

Hence, option D is correct.