Concept:Use substitution and partial fractions to integrate 1/(ex−1)2.Explanation:Let u=ex, so du=exdx=udx, hence dx=du/u.The integral becomes ∫u(u−1)21du.Partial fractions: u(u−1)21=u1−u−11+(u−1)21.Integrate: ln∣u∣−ln∣u−1∣−u−11+c=lnu−1u−u−11+c.Substitute back u=ex: ln(ex−1ex)−ex−11+c.Answer:ln[ex−1ex]−ex−11+c matches option C.