Final answer:
The sentence in the active voice is D. I consider myself a great student.
Step-by-step explanation:
The sentence in the active voice is: D. I consider myself a great student.
To determine if a sentence is in the active voice, you can ask yourself if the subject of the sentence is performing the action of the verb. In this case, the subject 'I' is considering 'myself' as a great student, so it is performing the action.
The other sentences are in the passive voice because the subjects are receiving the action.