In the story of Mephibosheth, the grandson of King Saul, what does David's treatment of him reveal about the nature of covenant loyalty and grace in the Davidic kingdom?

A David's kindness towards Mephibosheth was solely a political move to consolidate his power and appease Saul's remaining supporters. B David's acceptance of Mephibosheth, despite his lineage to a former enemy, demonstrates a commitment to upholding his covenant with Jonathan and extending grace even to those who might be considered threats. C David's actions were primarily motivated by fear of retribution from Saul's family if he mistreated Mephibosheth. D David's decision to care for Mephibosheth was based on Mephibosheth's physical ability to serve in the royal court.