A Stool Culture Was Received from a 34-Year-Old Male Who

A stool culture was received from a 34-year-old male who is experiencing diarrhea after a family reunion picnic. The food served included hot dogs, hamburgers, fried chicken, potato salad, baked beans, and various desserts. The image provided shows the Hektoen-enteric agar growth from his culture.
Source: CDC
Based on these results, your next step in the workup of this stool culture is to

A) perform testing to detect shiga toxin.
B) disregard it as normal flora.
C) perform Shigella serotyping.
D) identify using saline as the inoculum suspension.