Final answer:
To quickly respond to zero-day threats, an organization should use tools that support the STIX data standard, designed for the automated exchange of cyber threat intelligence.
Step-by-step explanation:
To best arm an organization's cybersecurity defensive suite with intelligence on zero-day threats shortly after they emerge, it would be beneficial to acquire tools and services that support the Structured Threat Information eXpression (STIX) data standard. STIX is specifically designed to convey the full range of potential threat information and is highly automated, enabling organizations to respond to new threats swiftly. While other standards mentioned, such as OVAL, XCCDF, CWE, and CVE, also play roles in cybersecurity, it is STIX that provides a comprehensive framework for the exchange of cyber threat intelligence.