Answer:
Diction can mean the "choice and use of words and phrases in speech or writing" and also "the style of enunciation in speaking or singing". Either way, it is related to how you speak. In the business world, you have to know the nuances of how to treat people with respect while commanding respect at the same time. You have to know when make things slightly less formal to cause proximity to others without making them feel offended or taking the risk of others finding you impolite. So, yes diction is very important because knowing what to say is always important.