In some tests a question is critical, ie. answering that question incorrectly makes you fail the whole test, even if that's your only wrong answer. I tried serching for 'sudden death question' but it does not seem to be the right term. So is there a name for such all-losing questions?
Learn English – the correct term for a must-answer-correctly question in a test
terminology
Best Answer
This is called a gating question. Think of the question as a gate to the rest of the test. If you don't get past the gate, the rest of the test doesn't matter. If you do, you still need to get past the rest of the test.