Procter & Gamble Introduced Old Spice High Endurance Antiperspirant, Targeted

Procter & Gamble introduced Old Spice High Endurance antiperspirant, targeted to teenage boys who don't watch much TV. P&G did grassroots marketing including handing out samples at skateboarding events and sponsoring a contest for the "high-school football player of the year." P&G emphasized which promotional element in this example?

A) sales promotion
B) advertising
C) personal selling
D) public relations
E) word of mouth