Which statement regarding the physical examination of tremor is TRUE?

a) Intention tremor is not related to a cerebellar problem.
b) A benign essential tremor improves with beta-blockers.
c) An action tremor improves with caffeine intake.
d) The action tremor seen with Parkinson's disease improves with beta-blockers.
e) The resting tremor in Parkinson's disease worsens with activity.