B?
They want me to add at least 20 characters for some reason so that's why I wrote this. You don't have to read it. Life is good.
The best answer among the following choices would be the second option B) Forensics because this classifies as the definition.
Answer: Spain and Portugal
Explanation: The subject is the who or what of the sentence. It's what the sentence is about. In this sentence, the places that are occupying the Iberian Peninsula are Spain and Portugal.
I was thinking between either C or D but D seems to make more sense to me.