39. The ignition delay associated with fuels of low ignition quality results in a late and more explosive start to the combustion period, which results in higher peak pressures and consequent rough and noisy operation. This means what？ (A) the ignition delay could increase the mean effective pressure of cycle (B) the more explosive start to the combustion period due to ignition delay could generate the higher peak pressure (C) the ignition delay associated with fuels of low ignition quality is beneficial for engine performance as it results in higher peak pressures (D) the ignition delay associated with fuels of low ignition quality could alleviate the noise generation