Horizen Is an Internet Service Provider

Horizen is an Internet service provider. It has started a promotional offer where its existing customers are given discounts on their next bill if they refer the Internet service to 20 other people whom they contact through social media and Internet forums. This is an example of:

A) creating multiple opinion leaders for a brand.
B) customizing the appeal for each individual.
C) identifying dissociative reference groups of individuals.
D) targeting networks of individuals.
E) influencing an individual's behavior by using information.