The question pertains to configuring Amazon CloudFront with Origin Groups for high availability. Origin Groups allow you to set up multiple origins that CloudFront can use to distribute content. In the event of an origin failure, CloudFront can automatically fail over to a secondary origin, ensuring continuous availability of your content.

The correct options from the provided content are:

1. CloudFront routes all incoming requests to the primary origin, even when a previous request failed over to the secondary origin. This means that CloudFront will always attempt to serve content from the primary origin first. If the primary origin is unreachable, CloudFront will then fail over to the secondary origin. However, once the primary origin is back online, CloudFront will resume routing all incoming requests to it, regardless of any previous failover.

2. CloudFront fails over to the secondary origin only when the HTTP method of the viewer request is GET, HEAD, or OPTIONS. This indicates that CloudFront's failover mechanism is limited to these specific HTTP methods. This is important for understanding the scope of CloudFront's failover capabilities, as it does not apply to all types of HTTP requests.

The incorrect options mentioned are:

• In the Origin Group of your distribution, all the origins are defined as primary for automatic failover in case an origin fails. This is incorrect because in an Origin Group, there must be a primary origin and at least one secondary origin. The primary origin is the first choice for CloudFront to serve content, and the secondary origin is used only in the event of a failure.

• To set up origin failover, you must have a distribution with at least three origins. This is also incorrect. While having multiple origins can provide redundancy, CloudFront does not require a minimum of three origins to set up origin failover. You can have an Origin Group with a primary origin and just one secondary origin.

• When there's a cache hit, CloudFront routes the request to the primary origin in the origin group. This statement is misleading. CloudFront will serve the cached content directly to the viewer without routing the request to the primary origin when a cache hit occurs. The routing to the primary origin is relevant when there is a cache miss, and CloudFront needs to request the content from the origin.

In summary, CloudFront's origin failover feature is designed to maintain high availability by automatically switching to a secondary origin when the primary origin fails. However, it is important to understand the limitations and conditions under which failover occurs, specifically that it is restricted to GET, HEAD, or OPTIONS HTTP methods and that CloudFront will always prefer the primary origin for serving content whenever possible.