Stormbreaker,a Spy Movie,details the Story of Alex Rider Who,after the Death

Stormbreaker,a spy movie,details the story of Alex Rider who,after the death of his uncle,is recruited as an M16 spy.Armed with a special set of gadgets,Rider's mission is to save millions of lives.In James Bond fashion,the Cross pen serves as one of the key gadgets in the film.The maker of Cross pens paid to have its pen featured in this movie.What is this an example of?

A) advertising
B) a sales promotion
C) paid-for public relations
D) product placement