Isaac Is Promoted to the Position of Supervisor in His

Isaac is promoted to the position of supervisor in his company. Later, he notices that Dexter, an employee, is jealous of his promotion, because he was also a candidate for the supervisory position that was given to Isaac. Which of the following steps should Isaac take up in order to solve this issue effectively?

A) Speak about this issue to top-level executives
B) Try to defuse the conflict by training Dexter to become a supervisor
C) Neglect Dexter's feelings and perform his job with honesty
D) Try to understand Dexter's perspective and ask for his support on important tasks