Final answer:
The employee at iAI has violated Code 2.3: Know and respect existing rules pertaining to professional work by spending hours on social media to sell personal items against the organization's policy.
Therefore, the correct answer is: option B). Code 2.3 Know and respect existing rules pertaining to professional work.
Step-by-step explanation:
If an employee of an organization named 'iAI' is spending hours trying to sell items on social media, which is against the company's social media use policy, the ACM code the employee has violated is Code 2.3: Know and respect existing rules pertaining to professional work.
According to the provided policies and the nature of the professional organization's codes of ethics, the employee's action does not align with the corporate responsibility to adhere to established guidelines.
Focusing on personal activities such as selling personal items during work hours detracts from the quality and efficiency expected from a professional standpoint and disregards the specified limits on social media use.