Service businesses face unique marketing challenges because services are delivered by people, making it difficult to assure consistent each time. the answer is not service i think the answer is quality choices are calibre, grade, quality, and value

Yes, Quality is should be your answer

Service businesses face unique marketing challenges because services are delivered by people, making it difficult to assure consistent quality each time.

As humans are imperfect and are prone to error, the quality of each service given can be different depending on the person who is giving it. Personal opinions and events of life can also swerve the quality a person can give.

For example, quality of a happy and well-rested worker would be a lot more better than that of a disgruntled, over-worked, and tired worker.

hope this helps

~Rise Above the Ordinary

the answer is . a novel has no sub-plot, but a novella does