Final answer:
Net Corporation is the plaintiff in the lawsuit against Omega, Inc., alleging breach of contract.
Step-by-step explanation:
In this case, Net Corporation is the plaintiff. A plaintiff is the party that initiates a lawsuit by filing a complaint against another party, known as the defendant. In this scenario, Net Corporation is alleging that Omega, Inc. breached a contract to sell them a computer system. Therefore, the correct answer is d-the plaintiff.