The correct answer is A. permanently.
The phrase “for good” means “permanently” or “for the last time.” In this context, the speaker is saying that they are leaving India and will not be returning. This could be for a number of reasons, such as finding a better job opportunity in another country, wanting to experience a new culture, or simply wanting to start a new life.
Option B is incorrect because it is possible to leave India for good without doing good for oneself. For example, someone might leave India to escape poverty or persecution.
Option C is incorrect because it is possible to leave India for good without doing good for the country. For example, someone might leave India to take advantage of better opportunities in another country.
Option D is incorrect because it is possible to leave India for good and still do good for others. For example, someone might leave India to start a new business that will create jobs in their home country.