Final answer:
The onus is on the employer to prove on a balance of probabilities that there was just cause for dismissing an employee in a legal dispute. The correct option is a.
Step-by-step explanation:
In a legal dispute concerning whether an employer had just cause to dismiss an employee, the onus is on the employer to demonstrate, on a balance of probabilities, that it had just cause for the dismissal. This means that the employer must present evidence that is more convincing to the judge or jury than the employee's evidence.
Unlike a criminal case, where the burden is to prove something beyond a reasonable doubt, in a civil matter such as employment termination, the proof only needs to show that it is more likely than not that the employer had a valid reason to terminate the employee.
Hence, Option a is correct.