During the execution of a software development project, you notice that several high-priority features are behind schedule. Upon investigation, you identify that the delay is caused by unforeseen technical debt that was not accounted for in the initial planning. As the project manager, which of the following actions should you take first to address the impact on the project's schedule?
Hire additional third-party vendors to work in parallel on the delayed features without revising the schedule.
Conduct a performance review of the development team to identify inefficiencies and assign blame.
Re-estimate the remaining project tasks to account for the technical debt and update the project schedule accordingly.
Request additional resources to accelerate work on the high-priority features.