The correct answer is D) Correct the cause of scoring and install a new shaft sleeve. The reasoning behind this is that localized scoring on a pump shaft sleeve indicates there is an issue with the pump's operation or maintenance that needs to be addressed. Simply reassembling the pump or adjusting the speed or lubrication (as in answers A and B) would not resolve the underlying problem causing the scoring. Instead, the root cause of the scoring should be identified and corrected, and the scored shaft sleeve should be replaced with a new one to prevent further damage to the pump. Answer C is incorrect because checking the alignment would not directly address the scoring issue.