Explanation:

- Option 1: "off"

- Typically used as a preposition to indicate removal or distance from a surface or location. Not suitable in this context.

- Option 2: "of"

- Indicates a relationship of belonging or connection. It is used correctly here to specify someone being cured of a disease.

- Correct answer.

- Option 3: "from"

- Implies origin or separation. Not typically used to describe curing a disease.

- Option 4: "for"

- Generally shows purpose or intent. It doesn't fit in the context of curing a disease.