This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
Corynebacterium diphtheriae can be grown within 6-8 hour on 
Select and explain. 
A. Potassiu, tellurite media with iron, B. McConkey's agar, C. Dorset egg medium, D. Loeffler's serum slope
D: Loeffler's serum slope
Answer: D: Loeffler's serum slope 
Explanation: The usual media employed for the cultivation of diphtheria bacilli are Loeffler's serum slope and Tellurite blood agar. Loeffler's serum slope: Diphtheria bacilli grow on Loeffler's serum slope very rapidly and colonies can be seen in 6-8 hours, long before other bacteria grow. Colonies are first small, circular white opaque discs but enlarge on continued incubation and may acquire a distinctly yellow tint. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 242