HEy PeEpSwill give da crown to someone u-u

D

Explanation:

This answer is correct; if you want you can use context clues, the middle two are not benefits, the first one is just absurd, so the only other logical answer id D. Also, its true.

The middle two are negative, and therefore cannot be benefits no matter how they are looked at.

For an explanation of the first answer and why it's wrong, read the comments.

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"