The list below are about various types of costs incurred in a typical business cycle. a. Cost of employees' visit to an exhibition to demonstrate the product b. Testing the product c. Payment to advertise the product d. Cost of component parts outsourced to be installed on the product Required: Classify each of the items above one of the business functions of the value chain, either (1) R&D, (2) design, (3) production, (4) marketing, (5) distribution, or (6) customer service.