Final answer:
The person Spot claims to have surrounded in the quote is Roosevelt.
Step-by-step explanation:
In the given question, the person who Spot points out as surrounded is D) Roosevelt. This information is mentioned in the provided text that states, 'Roosevelt won this race to the bottom by calling his former secretary of war a 'fathead' whose brain was less developed than that of a guinea pig.' Therefore, Roosevelt is the person who Spot claims to have surrounded.