Each of the following sentences has been divided into five parts (a), (b), (c), (d), and (e). One of these parts may contain a grammatical or idiomatic error. Identify the part that contains the error. If there is no error, choose option (e). Hardly had the negotiations concluded (a), when new evidence emerged (b), that contradicted earlier assumptions (c), forcing policymakers to reconsider their stance (d). No error (e)