The correct option is A Saccharomyces
Fermenting agents are Saccharomyces cerevisiae, S.sake, S.ellipsoidens. Molasses and fruit juice are more commonly used in brewing industry. Molasses is a dark coloured syrup left after the extraction of sugar. Yeasts are used as supplement to human food, Brewer's yeast is a readily available source of protein. At present the scientists are thinking of microscopic forms of food (fungi as a single cell protein) or atleast as food flavouring agent