Answer:
B. casual and relaxed.
Step-by-step explanation:
One characteristics of a great public speaker is that they tend to able to adjust their persona depended on the target audience. As the President of United States, Obama usually carried himself with a mixture of serious, professional, yet relaxed persona.
But, The Colbert Report is different compared to his usual political platform.
The Colbert Report was aired on Comedy Central. The target viewers for the shows was casual audiences who seek to laugh and be entertained. This was the reason why he changed his persona in order to cater to the audience into a casual and relaxed persona.