Answer: SALARY
Explanation: Frederick Herzberg an American psychologist developed the two-factor theory also known as the Herzberg's motivation-hygiene theory and dual-factor theory.
This theory explains that job satisfaction is largely based on two factors, satisfiers and dissatisfiers. He further explained satisfiers as things such as Performance, recognition, job status, challenging work, recognition for one's achievement, responsibility, opportunity to do something meaningful, involvement in decision making etc
while dissatisfiers as things such as salary, secondary working conditions, the relationship with colleagues, physical work place, relationship between supervisor and employee, insurance vacation etc.