He failed the test, ______ surprised everyone.

Answer and explanation

Correct answer: B. which

  1. Step 1: 'Which' can refer to a whole preceding clause.
Answer
which.
Why not the others: that, what and who don't fit.

Practise more Clauses and relatives.

Free questions with an explanation for every one, and full timed College English Test Band 4 (CET-4) - China mock tests.