Review the scenario below then answer the questions which follow:

Case Study - e-Commerce solution (online storefront) for ABC Ltd.
You are required to produce a design for an e-commerce solution (online storefront) for the retail company ABC Ltd.
This design must take the form of a UML class diagram. High-level requirements have been provided below.
ABC will use the solution to promote and sell the thousands of products listed in ABC’s product catalog. Though ABC expects to add other products in the near future the catalog currently includes books, DVDs, music CDs, apparel, consumer electronics, beauty products, kitchen items, jewelry, watches, garden items, and toys.

Potential customers must be able to visit the online storefront to:

• - Search or browse ABC’s product catalog
• - View product details (including description, price, customer ratings and reviews, etc.)
• - Manage their shopping cart (add products to cart, remove products, etc.)

In addition, registered customers must be able to login, manage their user account, check out/place orders, and submit reviews of items previously purchased. To register a customer user must complete and submit an online registration form, providing ABC with their email address, password, and one or more of each of the following, phone number, shipping address, billing address, and payment details.

ABC’s customer service, order fulfillment, and other employee users must also be able to use the system to support business operations.

Which of the following could be considered an example of a non-functional requirement for this scenario?

• The system shall notify users when an item has been successfully added to the shopping cart
• The system shall allow registered customers to place an order
• The system shall allow users to add an item to the shopping cart
• The system shall allow users to search for a product item