Salesperson: When a salesperson is successful, it is certain that that person has been in sales for at least three years.
Evidence
To succeed as a salesperson, one SS → SCB must first establish a strong client base.
Anyone who spends at least three 3 + Y → CL years developing a client base can eventually make a comfortable living in sales.
Conclusion
When a salesperson is successful, SS → 3 + Y it is certain that that person has been in sales for at least three years.
Evaluate
This argument assumes to have a SCB → 3 + Y strong client base one must spend at least three years developing that client base.