Final answer:
Manual legacy systems are usually not part of an ERP's core applications.
Step-by-step explanation:
The correct answer is 1) Manual legacy systems. An Enterprise Resource Planning (ERP) system is designed to integrate and manage all aspects of a business, including production development, purchasing, and sales and distribution applications. However, manual legacy systems are not typically part of an ERP's core applications, as they refer to outdated and manual processes that are not integrated into the ERP system.