This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Culture media and method, Subject name: Microbiology
[{'content': 'Agar is added to Broth medium: \nSelect and explain. \nA. To make the medium liquid, B. To make the medium solid, C. To provide extra nutrition to grow, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. To make the medium solida. Broth media can be made solid by adding agar, a gel like polysaccharide extracted from red algae,b. Broth with about 1.5% agar added will be liquid when heated, but solid at room temperature, making it easy to pour into a vessel, such as a Petri dish or test tube when hot.c. The solution then becomes solid once cooled.', 'role': 'assistant'}]