Afairly subtle approach to advertising is
a. product placement
b. television advertising
c. radio advertising
d. integrated marketing communications

A fairly subtle approach to advertising is "product placement".

Product placement refers to an advertising technique utilized by organizations to unpretentiously advance their items through a non-customary promoting method, more often than not through appearances in film, TV, or other media.  

Product placements are regularly started through an understanding between an item maker and the media organization in which the media organization gets monetary advantage. An organization will frequently pay an expense to have their item utilized, showed, or altogether included in a film or show.

answer; monopolistic competition;