The correct choice is (a) \(\int_0^τ\)(1-\(\frac{t}{τ}\))^3\(\frac{e}{t}^\frac{-t}{t}\) dt
Best explanation: For chemical reaction controlling, \(\frac{t}{τ}\) = 1-(1- XB)\(^\frac{1}{3}\). Hence, 1-\(\overline{X_{(B)}}\) = ∫0^τ(1-\(\frac{t}{τ}\))^3\(\frac{e}{t}^\frac{-t}{t}\) dt.