Answer:b. environmental context
Explanation: Context is crucial for the audience to understand your message or speech and for you to understand them.
There is a situational context which refers to why you are delivering your message
Environmental context is the actual physical environment where you deliver your speech and time of delivery. So it refers to the venue and the time you speak your message.
Being aware of your environment makes you connect well with your audience and know exactly how to effectively present your message.