The answer is C
Why:
A - this is natural
B - water is natural
D - this is also natural
C- this is right because when we breathe out we produce more carbon dioxide then we breathed in.
<span>A SI base unit is the single and direct measurement unit for a physical entity. E.g. For mass it is kg, for time it is sec, A derived unit is determined by a physical equation with the base units, like for velocity equals distance divided by time, in SI units: unit of v (velocity)= m (meter) divided by sec (seconds).
Hope this helps!</span>
The answer is 18.23432 grams.
Molar mass of KOH= 56.1056

= 18.234 grams