What type of marketing can a business utilize through social media?

Viral marketing is a strategy that leverages social media to spread information quickly and widely, ideally achieving rapid growth in brand awareness and consumer engagement. This type of marketing relies on creating compelling content that encourages users to share it within their networks, leading to exponential exposure and interaction without the need for substantial financial investment.

In contrast, other options like event planning, telemarketing, and cold calling do not harness social media in the same impactful way. Event planning may use social media for promotion but is not a form of marketing specific to social media platforms. Telemarketing and cold calling pertain to direct outreach strategies that do not involve online platforms, failing to tap into the broad audience that social media provides. Hence, viral marketing is the most relevant and effective approach to social media marketing among the choices given.