Answer:
A. elements
<em>I</em><em> hope</em><em> it's</em><em> helps</em><em> you</em>
Krypton-84 is the most abundant type of Krypton. The answer is C.
If you need this to be explained, I will do my best it's a bit difficult to say how to find it out, but I will if you need me to.
Hey there!
The answer is C. Tectonic plates, with the most famous of earthquakes being a plate called the "Ring of Fire"
Hopes this Helps u :D