Concept:Substitute x=t to convert the irrational integrand into a rational function in t.Explanation:Let x=t, so x=t2 and dx=2tdt.Then the integral becomesI=∫t2+1t⋅2tdt=∫t2+12t2dt.Rewrite the numerator as t2+1−1 to split the fraction:I=2∫(1−t2+11)dt.Now integrate term by term:I=2(t−tan−1t)+c.Substitute back t=x:I=2(x−tan−1x)+c.This matches option B.Answer:B. 2(x−tan−1x)+c, where c is a constant of integration.