Final answer:
The threat of a new entrant in the soft drink industry is exemplified by Zevia Natural Diet Soda starting to sell directly over the Internet, challenging established brands through new market strategies.
Step-by-step explanation:
When analyzing the soft drink industry using Porter's five forces model, the threat of a new entrant refers to the potential for new competitors to enter the market. The correct answer that represents a threat of a new entrant in the soft drink industry is: C. Zevia Natural Diet Soda begins selling directly over the Internet. This is because Zevia is a new company entering the market, which could potentially take market share from established firms like Coca-Cola and Pepsi. Large advertising budgets and brand recognition are significant barriers to entry for new firms since matching the promotional budgets and brand presence of giants like Coca-Cola and Pepsi is a daunting task. Additionally, product differentiation is crucial; firms may need to grow substantially before they can afford significant marketing expenditures to create recognizable brand names. Therefore, a new company like Zevia entering the market indicates a direct threat to the established players.