According to herzberg, a sense of achievement, earned recognition, and interest in the work itself were all:

According to herzberg, a sense of achievement, earned recognition, and interest in the work itself were all important motivators. 

Motivators are something that motivates or pushing a person to keep doing what they are doing. When you achieve something and receive recognition for it, you are likely going to keep working hard because it is nice to feel appreciated. Most people want to know that their hard work did not go unnoticed and when someone shows another individual that it didn't the hard work continues.

The correct answer is "bantu".