Answer:
There is no actual way that the mantle could be...'exposed' or 'seen'. But scientists have managed to find multiple ways to analyze the mantle and it's actual existence by using multiple devices. The mantle is basically a 2,900 kilometers (1,802 miles) thick blocks of rocks and minerals underneath the crust(or the surface of the earth) , and makes up a whopping 84% of Earth's total volume.
The option which would most likely result in the greatest decrease in the rate of a chemical reaction is adding an enzyme inhibitor to a reaction catalyzed by an enzyme.
Enzyme inhibitor is known for slowing down any processes, especially when it comes to chemical reactions, so I'd say A is the correct answer.
XYY disorder is a hereditary condition in which a human male has an additional male (Y) chromosome, giving an aggregate of 47 chromosomes rather than the more regular 46. The "XYY" chromosome hypothesis drop out of support as a clarification for criminal conduct is on account of thought most lawbreakers don't have XYY and everybody with XYY is not a criminal