Answer:
Retail banking is not a channel for delivering banking services; it's a type of service. The other options are direct channels such as mobile and online banking, ATMs, and branches.
Step-by-step explanation:
The options listed are all channels for delivering banking services, except for retail banking. While mobile banking, online banking, automated teller machines (ATMs), and branch banking are direct channels through which services are delivered, retail banking is not a channel but a type of banking services that cater to individual consumers rather than businesses. Therefore, the correct answer is 'e. Retail banking.' as it does not fit the category of a channel for delivering banking services.