For importing a large volume of data (over 100,000 records), the recommended tool is Data Loader with the Bulk API feature enabled. Data Loader is a client application designed for bulk data operations and can handle up to 5 million records. Enabling the Bulk API optimizes the process for large datasets by processing records in batches asynchronously, which is faster and more efficient in consuming API limits compared to the standard SOAP API used for smaller loads.

A. The Developer Console is a development and debugging tool, not a data import tool for large volumes of records.

C. An AppExchange package is a potential solution but not the standard, out-of-the-box tool. The question implies using native Salesforce functionality.

D. The Data Import Wizard is a user-friendly, web-based tool, but its processing limit is 50,000 records per job, making it unsuitable for this scenario.

1. Salesforce Help. (2024). Data Loader. "Use it to insert, update, delete, or export Salesforce records. When importing data, Data Loader reads, extracts, and loads data... For large numbers of records, we recommend you use Data Loader."

2. Salesforce Help. (2024). When to Use the Data Import Wizard. "Import up to 50,000 records at a time."

3. Salesforce Developer Documentation. (2024). Bulk API Developer Guide. "Bulk API is based on REST principles and is optimized for loading or deleting large sets of data." Section: Introduction to Bulk API.