Match column I with column II and select the correct answer:

column I	column II
a. Amoebiasis	1. Treponema pallidum
b. Diphtheria	2. Houseflies as mechanical carriers
c. Cholera	3. DPT vaccine
d. Syphilis	4. Oral rehydration therapy

A. a-2, b-1, c-3, d-4

B. a-2, b-3, c-4, d-1

C. a-1, b-2, c-3, d-4

D. a-1, b-4, c-2, d-3

Answer: Option B