I'll help as soon as I can but what's this question referring to? A book or?
Answer:
The deacidification process preserves pages by neutralizing acid with magnesium oxide, raising the pH level of the paper, and minimizing the alkaline reserve. (Choice 3)
Explanation:
Choice 1 is wrong because you don't need a comma after and. You don't set off coordinating conjunctions with a comma when you give a list of items.
Choice 2 is wrong because you need a comma <u>before</u> and, <u>not after</u> it.
Choice 4 is wrong because you use a comma before and in a list of three or more items. Sentence 4 contains three items but no comma before and, which is wrong.
