The correct option is B bacteria
Diphtheria is a bacterial disease caused by Corynebacterium diphtheriae. The bacteria gets transmitted from one to another person through contaminated droplets. The symptoms are weakness, sore throat, mild fever, and swollen glands in the neck. Treatment includes diphtheria antitoxin and antibiotics. It can be prevented through proper vaccination and public and maintaining personal hygiene. Usually a swab test is performed to diagnose this disease.