Positive Schick's test indicates that person is -: (A) Immune to diphtheria, (B) Hypersensitive to diphtheria, (C) Susceptible to diphtheria, (D) Carrier of diphtheria
Answer is C. Positive test means that person is susceptible to diphtheria: So immunization is required.
Shick Test

Ref: Apurba Sastry’s Essentials of Medical Microbiology 1/e p248, Ananthanarayan 9/e p 241