Answer:
a. conveys ideas more vividly.
Step-by-step explanation:
Option B is wrong because using an active voice cannot create an unpleasant thought. The active voice is simple and easy to use. Therefore, option B is incorrect.
Option C is incorrect either because active voice cannot hide anything. With the help of active voice, business communication becomes smooth.
As active voice provides a strong feeling in business, managers usually prefer active voice to convey the ideas more brightly. Therefore, Option A is correct.