Explanation
To show Component as a related list on Product, a lookup relationship on Component to Product should be created. A lookup relationship creates a loose association between two objects and allows users to relate records from one object to another. A lookup relationship also allows users to add the related list of the child object to the parent object's page layout.

Sharing rules can be used to extend access to records owned by certain users or roles to other users or roles. In this case, a sharing rule can grant read-only or read/write access to sales-owned accounts to the marketing team

The inability to create a Roll-Up Summary field in this context can be attributed to:
B . The organization has Advanced Currency Management enabled. When Advanced Currency Management (ACM) is enabled, it affects how currency data is managed and aggregated, impacting the functionality of roll-up summary fields that involve currency amounts across different records.
To address this limitation, consider using custom reporting or a custom solution like a trigger or a scheduled batch class to manually calculate and update the total.
For more information on limitations with ACM, consult Salesforce's help article on Advanced Currency Management.