Which approach will achieve this goal?

Explanations:

Using EC2 instances in multiple AWS Regions ensures high availability by distributing workloads across geographically separate locations. This protects against regional failures, including natural disasters, since different regions are isolated from each other.

Using EC2 instances in multiple Amazon CloudFront locations is not a valid approach for achieving high availability, as CloudFront is a content delivery network (CDN) that caches content at edge locations rather than providing infrastructure resilience for EC2 instances.

Using EC2 instances in multiple edge locations is also incorrect because edge locations are primarily used for caching and delivering content closer to users, not for hosting EC2 instances that require high availability in the face of regional disasters.

While AWS Local Zones provide low-latency access to applications closer to end-users, they do not provide the geographic redundancy needed to ensure high availability in the event of a natural disaster affecting a specific region.