A sales rep has a list of 300 accounts with contacts that they want to...

The Data Import Wizard is the ideal tool for importing a relatively small number of records (up to 50,000) when those records involve standard objects like Accounts and Contacts simultaneously. One of the unique strengths of the Data Import Wizard is its ability to handle "Account and Contact" imports in a single pass, automatically linking the contacts to the correct accounts based on name or site. Because the volume in this request is only 300 records, the Data Import Wizard provides a simple, browser-based interface that includes built-in duplicate checking, which is highly beneficial for maintaining data quality. While the Data Loader (Option D) and Dataloader.io (Option A) can also handle 300 records, they are typically reserved for much larger datasets (up to 5 million records) or more complex objects. The "Wizard" is the most user-friendly and efficient choice for this specific sales rep request.