Your question is Prioritize Testing Under Tight Deadlines. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You are responsible for QA on a medical imaging software release, and the delivery date cannot move. The build includes several changes across core workflow areas, but the available test window is shorter than planned, so you cannot execute every regression test at the same depth.
How would you prioritize testing tasks when given tight deadlines?