A philanthropist is a person who donates money to needy and poor people. He seeks to promote welfare of other by donating their money, time, experience, talent or skill to help others in creating a better world.
In the given case, all three of them are philanthropist as Mr A donated grain which he probably bought himself. Mr B has donated quilts on which he spend his money and Mr C donated his time and skill to educate the inmates about block printing as for them to learn a new skill. While some believe philanthropy only extends through donation of money but in reality it doesn’t matter in what way a person helps, as long they are willing to help their community and to make world a better place.