At Happywell, Inc. , last year the average annual salary for dieticians was $50, 000, while the average annual salary for physical therapists was $42, 000. The average annual salary for all Happywell employees last year was $40, 000. If the information above is correct, which one of the following conclusions can properly be drawn on the basis of it? ['There was no dietician at Happywell last year who earned less than the average for a physical therapist.', 'At least one Happywell employee earned less than the average for a physical therapist last year.', 'At least one dietician earned more than the highest-paid Happywell physical therapist last year.', 'There were more physical therapists than dieticians at Happywell last year.']