Final answer:
Business writers prefer an active voice to ensure clarity by making it clear who is performing the action in a sentence, whereas passive voice often obscures the actor.
Step-by-step explanation:
Business writers prefer an active voice because inactive-voice sentences often obscure the actor. When using the active voice, the subject of the sentence is responsible for the action, which results in clearer and more concise statements. By contrast, passive-voice sentences can make it unclear who is performing the action, which is sometimes purposeful, such as when a writer wants to omit the actor's identity. However, in business writing where clarity and brevity are valued, the active voice is preferred for its directness and effectiveness.