B is the best answer.
I hope this helps! :)
Answer:
4.75%
Explanation:
Because North America has more people on Visa's and other things
Precambrian rocks<span> are mostly covered by rock systems of more recent origin, but where visible they commonly display evidence of having been altered by intense </span>metamorphism<span>. Precambrian rocks often occur in shields, which are large areas of relatively low elevation that form parts of continental masses.</span>