40. Correct.  The answer is true.  Using the product rule: d/dt(t3lnt2)= 3t2lnt2 + 2t4/t2  = 3t2lnt2 + 2t2= 3t2*2lnt + 2t2.  Factor out 2t2  to get (3lnt + 1)2t2.  In general, d/dt[lnf(t)] = f'(t)/f(t) and ln(ta) = alnt.