Which of the following pairs is mismatched?

Identify the number of correct statements from the following:
$(1)$ Gene therapy is used in the treatment of $ADA$ deficiency.
$(2)$ Tetanus causes sustained muscle contraction. There is a lack of relaxation phase.
$(3)$ Cigarette smoking leads to asthma in the respiratory system.
$(4)$ $A$ transplanted kidney in a patient can fail due to cell-mediated immunity.
$(5)$ Serum globulin is an antibody.

Match the disease in column $I$ with the appropriate items (pathogen/prevention/treatment) in column $II$.

Column-$I$	Column-$II$
$(A)$ Amoebiasis	$(i)$ Treponema pallidum
$(B)$ Diphtheria	$(ii)$ Use only sterilized food and water
$(C)$ Cholera	$(iii)$ $DPT$ Vaccine
$(D)$ Syphilis	$(iv)$ Use oral rehydration therapy

Which of the following is mismatched?

Find the odd one out with respect to the disease causative agent:

Which one of the following is a mental disability?