11. A ship’s propulsion plant should be rated such that the desired ship speed can be attained withadditional power capabilities held in reserve to allow for a degradation of performance with time. In this regard, what factor summarized below is not considered?
(A) The fouling and roughening of hull.
(B) The global warming effects.
(C) The reductions in the performance of prime mover.
(D) The roughening of the working sections of propeller.