In a city, a large number of clubs organize Blood Donation Camps. You feel

The correct choice is: Some Clubs are really doing a very good job to serve the society

Blood donation camps save lives, so clubs that organise them are doing real service to society. Assuming, without evidence, that they sell blood or chase government money is cynical and unfair.

Hence the best response is ‘Some Clubs are really doing a very good job to serve the society’.