New PMP Question & Answers with explanation

A project manager is informally told that a possible union action will involve their project team. At this stage of the project, any delays will significantly impact the schedule and budget. The probability of this union action was assumed to be minimal and was, therefore, unanticipated. What should the project manager do?
Select one
Several months after the implementation of an approved change to manage a risk, a project manager learns that the change failed to achieve the expected result. This led to adverse consequences. What should the project manager have done to avoid this?
Select one
A local government provides subsidies for energy-efficient activities. An organization plans a project to install solar panels to reduce energy costs. After the solar panel project has started, the government announces that solar panels may not continue to qualify for subsidies. What should the project manager do?
Select one
A project must integrate with many other systems that different vendors are developing, and one of the vendors goes bankrupt. What should project manager do first?
Select one