Which of the following is a method for purchasing a fare on CTA?

Purchasing a fare using the Ventra app is an effective method that aligns with modern technology and convenience for riders of the Chicago Transit Authority (CTA). The Ventra app is designed specifically for transit users, allowing passengers to buy, manage, and reload their transit fares easily from their smartphones. This method enhances the travel experience by making it quicker and giving riders various payment options, including credit and debit cards. Such technology helps streamline the boarding process and minimizes the need for cash handling, making it a popular choice among commuters.

The other methods listed do not provide viable or comprehensive fare purchasing solutions. The bus driver's discretion does not represent a standard method for purchasing fares and can lead to inconsistencies in fare payment processes. Using a TikTok account is unrelated to fare purchasing and highlights a misunderstanding of the transit payment systems. Lastly, restricting fare purchase solely to cash payments excludes many users who prefer digital options or may not always carry cash, limiting accessibility and convenience for riders.