Which list includes only Standard Salesforce objects?

The choice that includes only Standard Salesforce objects is the list of Accounts, Campaigns, and Contacts. In Salesforce, Standard objects are predefined objects that come with the platform, fully integrated into the system, and are essential for the core functionality of Salesforce.

Accounts are used to represent companies or organizations, Contacts are individuals associated with those accounts, and Campaigns are used for managing marketing efforts. These objects are foundational to Salesforce's Customer Relationship Management (CRM) capabilities.

In contrast, the other options include terms that either refer to custom concepts or do not correspond to recognized Standard objects in Salesforce. For example, "Complaints" and "Bug Fixes" are not Standard Salesforce objects; they may refer to custom objects or terminology used by specific organizations but are not included out-of-the-box with Salesforce. "Projects" and "Tasks" might seem plausible, but "Projects" is also not a Standard object in Salesforce, highlighting the importance of recognizing the standardized nomenclature that Salesforce provides in its system.