Choose the correct relative pronoun: 'Data security measures, ______ directly affect market valuation, require systematic management.'
答案解析
Core concept: Non-restrictive relative clauses. 'Which' (B) is required after commas to introduce supplementary information. 'That' (A) cannot be used in non-restrictive clauses. 'What' (C) introduces noun clauses, and 'whom' (D) refers to people, both being contextually inappropriate.
正确答案：B