Which of the following statements regarding power is TRUE? Group of answer choices a. Power = force x velocity b. For concentric contraction, the larger the force, the smaller the velocity (think about moving a couch). c. For concentric contraction, the maximal power happens when force is around 90% P0. d. Answers a. and b. are TRUE. e. All of the above (answers a., b., and c. are TRUE)