Answer:
The answer is: A) self-service
Step-by-step explanation:
Self service can be defined as the serving of oneself.
This happens when a client serves himself with goods or services offered by a business without the aid of a waiter, clerk, attendant, etc.
Sometimes that same client might even pay for the goods or services by himself usually thorough electronic payment devices (credit cards, phone apps, etc.) , without any human cashier.