<em>Answer:</em>
<em>observer effect </em><em> </em>
<em>Explanation:</em>
<em>In psychology, </em><em>the observer effect is described as a phenomenon in which there's a possibility that a specific act or behavior of observation might affect the different properties of the thing (what) is being observed. Therefore, it can reflect effects depending on an entirely different nature utilizing a specific mechanism and context.</em>
<em>In other words,</em><em> it refers to the act of observation that can influence a particular phenomenon that is being observed.</em>
<em><u>The correct answer is observer effect.</u></em>
A. Led to the development of two distinct groups.
(Federalists and Democratic- Republicans)
