C. Composition
is the answer
Most rocks that we encounter in our normal everyday lives are sedimentary rocks. Sedimentary rocks are rocks that have been worn down gradually over long periods of time. Because it takes very long periods of time (couple decades) for these rocks to change, it often seems as if they don't change at all, when in reality the change is too small for us to realize it!
The chemical formula for the compound strontium sulphide would be SrS.
Answer:

Explanation:
Here, we want to convert J to cal
Mathematically:

Thus, to get our answer in cal, we divide the value given by 4.186
We have that as: