The call to API of "https://api.amp.cisco.com/v1/computers" allows us to fetch list of computers across your organization that Advanced Malware Protection (AMP) sees. Reference: https://api-docs.amp.cisco.com/api_actions/details?api_action=GET+%2Fv1% 2Fcomputers&api_host=api.apjc.amp.cisco.com&api_resource=Computer&api_version=v1 Reference:
The call to API of "https://api.amp.cisco.com/v1/computers" allows us to fetch list of computers across your organization that Advanced Malware Protection (AMP) sees. Reference: https://api-docs.amp.cisco.com/api_actions/details?api_action=GET+%2Fv1% 2Fcomputers&api_host=api.apjc.amp.cisco.com&api_resource=Computer&api_version=v1

the routing of traffic through the Cisco Umbrella network is to browse to http://welcome.umbrella.com/.
This URL will display a message that confirms whether the new network identity is working or not.
If the message says "You're protected by Cisco Umbrella", then the traffic is being routed correctly.
If the message says "You're not using Cisco Umbrella", then the traffic is not being routed correctly and the configuration needs to be checked. The other options are not valid actions to test the routing. Option A is incorrect because the client computers should point to the Cisco Umbrella DNS servers, not the on-premises DNS servers. Option B is incorrect because the Intelligent Proxy is a feature that selectively intercepts and proxies web requests for deeper inspection, not a tool to test the routing. Option C is incorrect because adding the public IP address to a Core Identity is a way to identify the network, not a way to test the routing. References:
* How To: Successfully test to ensure you're running Umbrella correctly
* Add a Network Identity

Trusted Automated eXchange of Intelligence Information (TAXII) is a collection of services and message exchanges that enable the sharing of cyber threat intelligence across product, service, and organizational boundaries. It is designed to support the exchange of CTI represented in STIX, but is not limited to STIX.
TAXII defines an API that aligns with common sharing models, such as hub-and-spoke, peer-to-peer, and subscribe/publish. TAXII is not a public collection of threat intelligence feeds, a threat intelligence sharing organization, or a language used to represent security information. Those are possible descriptions of STIX, which is a complementary standard to TAXII. References: STIX and TAXII Approved as OASIS Standards to Enable Automated Exchange of Cyber Threat Intelligence, STIX V2.1 and TAXII V2.1 OASIS Standards are published, What is STIX/TAXII? | Cloudflare, What is STIX / TAXII? Learn about the industry standards for Cyber ..., What are STIX/TAXII Standards I Resources I Anomali