Final answer:
The collection of cash from customers is classified as an operating activity because it reflects the company's earnings from normal business operations.
Step-by-step explanation:
The collection of cash from customers classifies as an operating activity. Operating activities are the principal revenue-producing activities of the business and other activities that are not investing or financing activities. Therefore, when a company collects cash from its customers, it's considered part of the day-to-day business operations. This cash inflow reflects the earnings from normal business operations.