I believe the answer is C. But I am not quite sure
Answer:
I think whom. Since it sounds better then who in that sentence.
The correct answer is C.
In order to understand an informational text we have to make sure we truly comprehend it.
The best way to make sure we know what the text is about is discovering the author's purpose. In order to have a better understanding we can ask ourselves questions like: "what is the author's opinion on this subject?"
The answer is a) preposition
Have* this is because has* is past tense and have is more appropriate since there are multiple things you are referring too (Mercury, Venus, Earth and Mars). To be honest, these planets have a molten core.
