Plz help I give brainliest

This question awards 100 ! i really don’t want to fail i will also mark you !

An energy drink company claims that its product increases students' memory levels. to support its claims, the company issues advertisements claiming that 8 out of 10 people (chosen randomly from across the country) who tried their product reported improved memory. the missing component in this study is a .

    choose the correct definition for  extremo.  a.  end      b.  extra      c.  extract      d.  eventual