A Day Shift Microbiologist Encounters an Oxidase Negative, Non-Lactose Fermenter

A day shift microbiologist encounters an oxidase negative, non-lactose fermenter in a urine culture. To determine if it is a member of the Enterobacteriaceae or a nonfermenter, he sets up a TSI agar slant. After 10 hours of incubation at 35°C in ambient air, the evening shift microbiologist reads the tube as a yellow slant and yellow deep or butt. This result

A) indicates a member of the Enterobacteriaceae.
B) indicates a nonfermenter.
C) could be due to a gram-positive organism. Perform a Gram stain.
D) is invalid.