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.
Well, first off it tells you the number of valence electrons (because that’s what those are valence electrons) it also tells you how that atom is going to bond with other atoms (whether it will tend to loose or gain electrons when in chemical bonds). It also can show how reactive an element is (if it has eight or in some cases two then it won’t react because that outer shell is full)...basically it tells you the chemical properties of that atom
