Which of the following is an example of consumer-to-consumer electronic commerce?

Consumer-to-consumer electronic commerce, also known as C2C, involves transactions where consumers sell goods or services directly to other consumers through an online platform. In the provided example, Marty purchasing Lobsang's mountaineering equipment from eBay.com exemplifies this concept perfectly. eBay acts as a marketplace where individual sellers (like Lobsang) can list items for sale, and buyers (like Marty) can browse and purchase those items directly from the seller, facilitating a transaction between two consumers without the involvement of a traditional retailer or intermediary.

This scenario highlights the essence of C2C e-commerce, as it shows the direct exchange of goods between two individuals using an online platform. While other choices involve different types of transactions, they do not reflect the consumer-to-consumer model. For instance, a deposit into a friend's account is a personal transaction without a commercial exchange, buying from a site like Amazon involves a consumer purchasing from a retailer, and conducting business with retailers pertains to business-to-business transactions.