Just want my points sorry it’s probably A
A im guessing? soz if i get it wrong.
Answer:
I say, it would really be around like 50-500km. Really, it would be 70km.
Explanation:
Magma rises with convective currents, then cools and spreads intent on form ocean-floor crust. The place to start for melting has lengthy been idea to be at <em>70 kilometers</em> under the seafloor.
It is definitely not a primary source: this would be a book itself.
Now, is it a tertiary source? I don't think so: the author of the review should have read the book and should only be referring to this book in the review.
I think it's a secondary source.
