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 usage error. Identify the part that contains the error. If the sentence is correct, choose Option (e) – No error.  The director described the mistake as a major big blunder (a) / that could have easily been avoided (b) / if proper verification procedures (c) / had been followed earlier (d). / No error (e)