Beyond the well-known narrative of his encounter with Goliath, how did David specifically demonstrate loyalty to King Saul, even when given opportunities to harm him?

A David publicly criticized Saul's military strategies, hoping to provoke him into retirement. B David refused to harm Saul, even when Saul was vulnerable and his advisors urged him to seize the throne. C David secretly negotiated with the Philistines, offering them a truce in exchange for their support. D David spread rumors of Saul's incompetence to undermine his authority and gain popular support.