Ans. is 'a' i.e., Blood agar Sore throat in childreno Sore throat refers to irritation or pain in the throat. The most common and usual cause is acute pharyngitis.o Infection is the most common cause of sore throat and etiological agents are usually respiratory viruseso The causes are -# Viral pharyngitis (70%) The most common being rhinovirus (40%) followed by coronavirus (10-20%), adenovirus (10%), herpesvirus (8%) and other virus (< 5%) like influenza, parainfluenza, EBV etc.# Streptococcal pharyngitis (20-30%) This is the most common bacterial cause.# Other causesH. influenzae, pneumococcus etc.o For diagnosis, the throat culture is performed by culturing the swab for bacteria collected from the back of throat. The bacteria are allowed to grow on special plates called sheep blood agar plateo However, throat culture takes 1 -2 days. Therefore, more rapid test, i.e. rapid antigen test (Quick test) can be used early if suspecting bacterial pharyngitis.