Answer: c. Mark. Since he captured the animal.
Step-by-step explanation:
With regards to the information given, the owner of the animal is Mark because he's the one who captured the animal.
It should be noted that the fact that Mike tells Mark that Mike has spent 25 years and $2,000,000 to corner the animal in a specific field in Congo doesn't mean that he's the owner of the animal.
Upon capturing the animal, under the law of ownership, the animal now belongs to Mark as he's the owner.