Create a new MCAE business unit, recreate the configuration, and link it to a full copy Sales Cloud sandbox. This way, users can test the lead nurturing with Engagement Studio, the forms on the website, and the lead management in Sales Cloud without affecting the production data or settings23.
The recommended approach for setting up an environment in which users can test the functionalities of Marketing Cloud Account Engagement would be to create a new Marketing Cloud Account Engagement business unit, synchronize the production unit and the training unit, and link it to a full copy Sales Cloud sandbox. This allows for a dedicated training environment that can be synchronized with the production environment to ensure that data and configurations are consistent between the two. Additionally, linking it to a full copy Sales Cloud sandbox enables end-to-end testing of the solution. (Reference: Salesforce Help - Create a Marketing Cloud Account, https://help.salesforce.com/s/articleView?id=sf.mc_create_account.htm&type=5)

Salesforce Sales Cloud is the system of record for the sales process because it contains information about opportunities and opportunity products, which are used for forecasting and reporting. It also integrates with other clouds such as B2B Commerce and CPQ to support the cart-to-quote process.
https://help.salesforce.com/s/articleView?id=icx_b2c_crosscloudengagement_systems_of_record.htm&language=en_US&type=5 In the described sales process, Salesforce Sales Cloud serves as the system of record. This is because the overall pipeline, including opportunities and opportunity products, which are central to forecasting and sales management, is managed within Sales Cloud. While CPQ and B2B Commerce play crucial roles in quoting and online purchasing respectively, and the ERP system houses product and primary pricing information, it is Sales Cloud that integrates these elements to provide a comprehensive view of the sales pipeline and performance. This alignment with sales processes makes Sales Cloud the authoritative source for sales-related data and activities, aligning with Salesforce's best practices for sales management and forecasting.

https://appexchange.salesforce.com/appxListingDetail?listingId=a0N3u00000MSk6gEAD Implement B2B Commerce on Experience Cloud to allow customers to purchase simple products with Add complex product configurations in a follow-up phase. This option would allow UC to quickly launch a self-service site for their customers to buy simple products online, while also leveraging the existing Sales Cloud data and processes for Opportunities, Quotes, and Orders. In a follow-up phase, UC can use the Salesforce CPQ and B2B Commerce for Lightning Experience Connector1 to enable customers to configure complex products on their site and sync them with Sales Cloud2.
Implement Salesforce CPQ internally first, then build "product configurator" functionality in a custom Experience Cloud site in a follow-up phase. This option would allow UC to streamline their internal sales process for complex products using Salesforce CPQ, while also maintaining their existing Sales Cloud data and processes for Opportunities, Quotes, and Orders. In a follow-up phase, UC can build custom "product configurator" functionality on their Experience Cloud site using Apex or Lightning Web Components and integrate it with Salesforce CPQ using APIs3.

For Universal Containers' requirements of sending scheduled emails and tracking opens, Marketing Cloud Account Engagement (formerly Pardot) is the recommended solution. It is specifically designed for B2B marketing automation, including email campaigns, lead nurturing, and engagement tracking. Marketing Cloud Account Engagement can handle the variable volume of emails and provides detailed analytics on email interactions, ensuring UC can effectively communicate with its audience and gain insights into campaign performance, in line with Salesforce's marketing automation best practices.

Option B would help resellers find answers to their questions by showing them relevant articles or discussions before they create a case. This way, they can resolve their issues without contacting support13.
Option D would help resellers learn how to use the site effectively and avoid common pitfalls. This way, they can reduce errors and confusion that might lead to unnecessary cases2.