Step 1: Understand the question:
A sales trainee is a new person who is still learning the sales job.
We must find the form of pay given at this stage.
Step 2: Recall the rule:
A trainee does not yet sell much, so sales-based pay would be very low or zero.
A fixed pay gives the trainee a steady income while he learns. This fixed pay is called salary.
Step 3: Check option (A) Salary:
Salary is a fixed amount paid at regular intervals, whatever the sales are. It suits a trainee. So (A) is correct.
Step 4: Why the other options are wrong:
Commission is a share in sales. A trainee with few sales would earn almost nothing.
Bonus is an extra reward for good work or for profits. A learner has not earned it yet.
Incentive is an extra payment for exceeding targets. It also needs results.
Final Answer:
Sales trainees are paid salary, which is option (A).