The Identification and Reconciliation Engine (IRE) is a core platform capability in ServiceNow and does not require CMDB 360 / Multisource CMDB to function. Even without the ITOM Discovery license, organizations can still define and use IRE reconciliation rules across multiple data sources.
IRE rules are source-aware and can evaluate attributes based on source precedence, regardless of whether CMDB 360 is enabled. CMDB 360 enhances visibility, governance, and monitoring of multiple sources, but it is not a prerequisite for reconciliation logic itself.
Option A is incorrect because purchasing ITOM Discovery is not mandatory to use multisource reconciliation. Option C is also incorrect because CMDB 360 / Multisource CMDB is a licensed add-on, not a universally available platform feature.
Therefore, the Data Owner can proceed by configuring IRE reconciliation rules directly, making Option B the correct answer.