Which medical treatment facility (MTF) catalog record tab is used to change an item's default source?

The LOG CAT tab in a medical treatment facility (MTF) catalog record is crucial for managing the logistical aspects of medical supplies. Specifically, this tab is used to modify various characteristics related to an item, including its default source. Changing the default source allows facilities to adjust where they will order the item from, which can be essential for inventory management, cost-effectiveness, and ensuring that the supply chain remains efficient.

This tab is primarily focused on the logistical information of the items listed, making it the appropriate choice when dealing with aspects related to sourcing items. Other tabs like Item Description, Item Availability, and Pricing Information serve different purposes, such as detailing product characteristics, assessing stock levels, or reviewing costs, but they do not directly facilitate changing the default source. Thus, the LOG CAT tab stands out as the correct answer for this question.