Comprehensive and Detailed In-Depth Explanation:

The custodian in SAP EWM manages stock ownership without title transfer, often in consignment scenarios. Option C ('The custodian processes stock without transfer of title') is correct, as defined in the stock attributes and configured in SPRO: SCM Extended Warehouse Management > Master Data > Define Custodian. Options A (putaway strategy), B (Supply Chain Unit), and D (legal possession) are incorrect as they misalign with the custodian's role, which is operational rather than strategic or legal.