What Is the Benefit of Reading an Abstract

What is the benefit of reading an abstract

A)  It can be quickly scanned to determine whether the rest of the article is relevant for your purposes. 
B)  It shows a detailed description of the research methods that the researchers used. 
C)  It provides you with all of the results and detailed statistics, so you can determine whether the results are significant. 
D)  It summarizes all the research that led the researchers to their current hypothesis.