A doctor takes some bacteria from an infected patient. These bacteria are cultured in a Petri dish that contains nutrient agar jelly. The bacteria form a grey layer on the agar jelly. The doctor then places three paper discs, each with a different antibiotic, onto the dish. The diagram shows the Petri dish after 24 hours. What conclusion can the doctor draw from these results?
- AThe bacteria causing this patient’s infection are not resistant to antibiotic Y.
- BAntibiotic X would be more effective than antibiotic Y for treating this patient’s infection.
- CThis patient is resistant to antibiotic Z.
- DAntibiotic X is the least effective treatment for this patient’s infection.