Which of the following tests would be useful in identifying escherichia coli? a. e. coli is a gram-negative bacillus that ferments lactose and glucose, but not sucrose. it is motile and does not utilize citrate or urea. b. e. coli is a gram-negative diplococcus that ferments lactose and glucose, but not sucrose. it is motile and breaks down citrate. it cannot produce urease. c. e. coli is a gram-negative bacillus that ferments glucose and sucrose, but not lactose. it is nonmotile and can produce urease, but it does not utilize citrate. d. e. coli is a gram-negative bacillus that ferments glucose and sucrose, but not lactose. it is motile and does not utilize citrate or urea. a