Answer:
A. Professional
Explanation:
The only answer to this question would be a professional tone. You can automatically eliminate C and D as an option because the question clearly says you are giving a presentation for a business audience, not to children. A business audience means business, in other words, formal. You might be excited on the inside (or maybe nervous) but you don't want to let that take over during the presentation because the audience isn't there to see an excited presentation. Punctual might seem like an option but it doesn't exactly describe a tone since it is mostly being on time. That is also important but being professional also includes being punctual and it is also makes one seem skillful, efficient, competent, and what-not. So, A. Professional would be the best option.
