Answer:
d
Explanation:
measures hydrogen ion concentration
The pH of a solution is a measure of the concentration of hydrogen ions in the solution. A solution with a high number of hydrogen ions is acidic and has a low pH value. A solution with a high number of hydroxide ions is basic and has a high pH value. The pH scale ranges from 0 to 14, with a pH of 7 being neutral.
Carbon would be the answer to this because it is an element while water is a compound. In addition, carbon had 4 bonding sites which allows it to form a variety of molecules like sugars, proteins, and even DNA that are essential for life as we know it.
Hold on let me go do my research I’ll brb .
I believe the answer you're looking for is cellular respiration.