In Oracle Data Integrator, one master repository can contain multiple work repositories. Work repositories store development and runtime objects, while the master repository stores security and topology information. The statement in the question is false.
In Oracle Data Integrator (ODI), a single Master Repository (holding topology and security metadata) can be linked to multiple Work Repositories — e.g., separate ones for development, QA, and production, or per-project execution repositories. So the claim that one master repo "can not" contain more than one work repo is false, and False is correctly marked.