The descriptions stated below refer to various methods of advertisements. For each description, give the method that best matches it.
a)Any mention of a person/firm or product in the mass media
b)Presentation of a commodity to the prospective buyers , face to face by sales person with an aim of making sales
c)Process of information with a view of creating, promoting or maintaining good will and favourable image of the organization to the public
d)Any paid form of impersonal presentation of a product made through mass communication to the public