The correct answers are:
(B) Poverty for most Russians
(C) Food shortages
(D) The writing of Karl Marx
<span> this method, which can use over 100 questions, gathers : biodata
Biodata is a set of file that consist of factual information about an individual, including facts such as name, age, gender, hobby, height, marital status, favorite song, etc.Researcher often use biodata to screened out the potential subject for their research</span>
<em>Answer:</em>
<em>two </em>
<em>Explanation:</em>
<em>In research methods,</em><em> the correlational study is referred to as one of the different types of research designs or methods whereby a researcher attempts to understand the kind or type of relationships various naturally occurring "variables" possess with each other. In other words, a correlation study design attempts to figure-out in what way two or more than two variables are being related to each other.</em>
<em>According to the question above, the correct answer would be "two".</em>