What must be done if the Government changes its requirements or terms and conditions after receiving proposals?

When the Government changes its requirements or terms and conditions after receiving proposals, the appropriate action is to amend the solicitation. This amendment is crucial as it ensures that all offerors are made aware of the changes and that any proposal evaluations or subsequent decisions are based on the most current and accurate information available.

Amending the solicitation provides a formal process for communicating changes, thus maintaining fairness and transparency within the competitive bidding process. This means that all interested parties have the opportunity to review the updated requirements and adjust their proposals accordingly, thereby ensuring a level playing field for all competitors.

The other options reflect actions that would not directly address the requirement to formally update the solicitation in response to changes made by the Government. While notifying selected offerors or changing evaluation criteria might seem relevant, they do not ensure that all participants are informed or that the solicitation remains valid and compliant with the revised terms. Canceling the RFP is also an extreme measure that would eliminate the entire procurement process rather than adjust it to reflect necessary changes. Therefore, amending the solicitation is the most appropriate response in this context.