Parietal cells within the stomach lining secrete hydrochloric acid that lowers the pH of the stomach. A low pH (1.5 to 2) activates pepsin. Acetylcholine, gastrin, and histamine stimulate the proton pump in parietal cells to release hydrogen ions and decrease pH.
6CO^2 + 6H2O—->sunlight C6H12O6+6O2
The answer to your question is both C
Answer:
D. Type in human immune system + HIV effects.
Explanation:
Since Angela is focusing more on the human immune system and the effects of HIV could have on it, the keywords combination that would produce the most relevant search result has to contain human, immune system and HIV effects.
Option A has human, body systems and HIV, immune is absent.
Option B contains immune system and human, no HIV effects.
Option C contains HIV and immune system, no human.
All the options are lacking in some ways and will not produce the most relevant search results.
The correct option is D. It has all the necessary keywords.
