Final answer:
Effective purchasing systems is not a primary objective of internal control according to COSO; rather, COSO's main objectives are efficiency and effectiveness of operations, compliance with laws and regulations, and reliable financial reporting.
Step-by-step explanation:
The question seeks to identify which option is not a primary objective of internal control as defined by the Committee of Sponsoring Organizations of the Treadway Commission (COSO). COSO identifies three main objectives of internal control: efficiency and effectiveness of operations, compliance with laws and regulations, and reliable financial reporting. Hence, effective purchasing systems is not listed as a primary objective by COSO, which focuses on broader goals rather than specific procurement processes.